linux-stable.git/net/ipv6, branch v5.4.232 Linux kernel stable tree ipv6: Fix tcp socket connection with DSCP. 2023-02-22T11:50:41+00:00 Guillaume Nault gnault@redhat.com 2023-02-08T17:14:03+00:00 e71554a09edf03ef01acc013e8835ee01d5c6063 commit 8230680f36fd1525303d1117768c8852314c488c upstream. Take into account the IPV6_TCLASS socket option (DSCP) in tcp_v6_connect(). Otherwise fib6_rule_match() can't properly match the DSCP value, resulting in invalid route lookup. For example: ip route add unreachable table main 2001:db8::10/124 ip route add table 100 2001:db8::10/124 dev eth0 ip -6 rule add dsfield 0x04 table 100 echo test | socat - TCP6:[2001:db8::11]:54321,ipv6-tclass=0x04 Without this patch, socat fails at connect() time ("No route to host") because the fib-rule doesn't jump to table 100 and the lookup ends up being done in the main table. Fixes: 2cc67cc731d9 ("[IPV6] ROUTE: Routing by Traffic Class.") Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 8230680f36fd1525303d1117768c8852314c488c upstream.

Take into account the IPV6_TCLASS socket option (DSCP) in
tcp_v6_connect(). Otherwise fib6_rule_match() can't properly
match the DSCP value, resulting in invalid route lookup.

For example:

  ip route add unreachable table main 2001:db8::10/124

  ip route add table 100 2001:db8::10/124 dev eth0
  ip -6 rule add dsfield 0x04 table 100

  echo test | socat - TCP6:[2001:db8::11]:54321,ipv6-tclass=0x04

Without this patch, socat fails at connect() time ("No route to host")
because the fib-rule doesn't jump to table 100 and the lookup ends up
being done in the main table.

Fixes: 2cc67cc731d9 ("[IPV6] ROUTE: Routing by Traffic Class.")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipv6: Fix datagram socket connection with DSCP. 2023-02-22T11:50:41+00:00 Guillaume Nault gnault@redhat.com 2023-02-08T17:13:59+00:00 388886f9708e188953a38c18642cd7a62541583c commit e010ae08c71fda8be3d6bda256837795a0b3ea41 upstream. Take into account the IPV6_TCLASS socket option (DSCP) in ip6_datagram_flow_key_init(). Otherwise fib6_rule_match() can't properly match the DSCP value, resulting in invalid route lookup. For example: ip route add unreachable table main 2001:db8::10/124 ip route add table 100 2001:db8::10/124 dev eth0 ip -6 rule add dsfield 0x04 table 100 echo test | socat - UDP6:[2001:db8::11]:54321,ipv6-tclass=0x04 Without this patch, socat fails at connect() time ("No route to host") because the fib-rule doesn't jump to table 100 and the lookup ends up being done in the main table. Fixes: 2cc67cc731d9 ("[IPV6] ROUTE: Routing by Traffic Class.") Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit e010ae08c71fda8be3d6bda256837795a0b3ea41 upstream.

Take into account the IPV6_TCLASS socket option (DSCP) in
ip6_datagram_flow_key_init(). Otherwise fib6_rule_match() can't
properly match the DSCP value, resulting in invalid route lookup.

For example:

  ip route add unreachable table main 2001:db8::10/124

  ip route add table 100 2001:db8::10/124 dev eth0
  ip -6 rule add dsfield 0x04 table 100

  echo test | socat - UDP6:[2001:db8::11]:54321,ipv6-tclass=0x04

Without this patch, socat fails at connect() time ("No route to host")
because the fib-rule doesn't jump to table 100 and the lookup ends up
being done in the main table.

Fixes: 2cc67cc731d9 ("[IPV6] ROUTE: Routing by Traffic Class.")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dccp/tcp: Avoid negative sk_forward_alloc by ipv6_pinfo.pktoptions. 2023-02-22T11:50:40+00:00 Kuniyuki Iwashima kuniyu@amazon.com 2023-02-10T00:22:01+00:00 0c2651c763695557be25a2614b973db891b8ba42 commit ca43ccf41224b023fc290073d5603a755fd12eed upstream. Eric Dumazet pointed out [0] that when we call skb_set_owner_r() for ipv6_pinfo.pktoptions, sk_rmem_schedule() has not been called, resulting in a negative sk_forward_alloc. We add a new helper which clones a skb and sets its owner only when sk_rmem_schedule() succeeds. Note that we move skb_set_owner_r() forward in (dccp|tcp)_v6_do_rcv() because tcp_send_synack() can make sk_forward_alloc negative before ipv6_opt_accepted() in the crossed SYN-ACK or self-connect() cases. [0]: https://lore.kernel.org/netdev/CANn89iK9oc20Jdi_41jb9URdF210r7d1Y-+uypbMSbOfY6jqrg@mail.gmail.com/ Fixes: 323fbd0edf3f ("net: dccp: Add handling of IPV6_PKTOPTIONS to dccp_v6_do_rcv()") Fixes: 3df80d9320bc ("[DCCP]: Introduce DCCPv6") Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit ca43ccf41224b023fc290073d5603a755fd12eed upstream.

Eric Dumazet pointed out [0] that when we call skb_set_owner_r()
for ipv6_pinfo.pktoptions, sk_rmem_schedule() has not been called,
resulting in a negative sk_forward_alloc.

We add a new helper which clones a skb and sets its owner only
when sk_rmem_schedule() succeeds.

Note that we move skb_set_owner_r() forward in (dccp|tcp)_v6_do_rcv()
because tcp_send_synack() can make sk_forward_alloc negative before
ipv6_opt_accepted() in the crossed SYN-ACK or self-connect() cases.

[0]: https://lore.kernel.org/netdev/CANn89iK9oc20Jdi_41jb9URdF210r7d1Y-+uypbMSbOfY6jqrg@mail.gmail.com/

Fixes: 323fbd0edf3f ("net: dccp: Add handling of IPV6_PKTOPTIONS to dccp_v6_do_rcv()")
Fixes: 3df80d9320bc ("[DCCP]: Introduce DCCPv6")
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipv6: ensure sane device mtu in tunnels 2023-02-06T06:52:51+00:00 Eric Dumazet edumazet@google.com 2022-10-24T02:01:24+00:00 af51fc23a03f02b0c6df09ab0d60f23794436052 commit d89d7ff01235f218dad37de84457717f699dee79 upstream. Another syzbot report [1] with no reproducer hints at a bug in ip6_gre tunnel (dev:ip6gretap0) Since ipv6 mcast code makes sure to read dev->mtu once and applies a sanity check on it (see commit b9b312a7a451 "ipv6: mcast: better catch silly mtu values"), a remaining possibility is that a layer is able to set dev->mtu to an underflowed value (high order bit set). This could happen indeed in ip6gre_tnl_link_config_route(), ip6_tnl_link_config() and ipip6_tunnel_bind_dev() Make sure to sanitize mtu value in a local variable before it is written once on dev->mtu, as lockless readers could catch wrong temporary value. [1] skbuff: skb_over_panic: text:ffff80000b7a2f38 len:40 put:40 head:ffff000149dcf200 data:ffff000149dcf2b0 tail:0xd8 end:0xc0 dev:ip6gretap0 ------------[ cut here ]------------ kernel BUG at net/core/skbuff.c:120 Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP Modules linked in: CPU: 1 PID: 10241 Comm: kworker/1:1 Not tainted 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022 Workqueue: mld mld_ifc_work pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : skb_panic+0x4c/0x50 net/core/skbuff.c:116 lr : skb_panic+0x4c/0x50 net/core/skbuff.c:116 sp : ffff800020dd3b60 x29: ffff800020dd3b70 x28: 0000000000000000 x27: ffff00010df2a800 x26: 00000000000000c0 x25: 00000000000000b0 x24: ffff000149dcf200 x23: 00000000000000c0 x22: 00000000000000d8 x21: ffff80000b7a2f38 x20: ffff00014c2f7800 x19: 0000000000000028 x18: 00000000000001a9 x17: 0000000000000000 x16: ffff80000db49158 x15: ffff000113bf1a80 x14: 0000000000000000 x13: 00000000ffffffff x12: ffff000113bf1a80 x11: ff808000081c0d5c x10: 0000000000000000 x9 : 73f125dc5c63ba00 x8 : 73f125dc5c63ba00 x7 : ffff800008161d1c x6 : 0000000000000000 x5 : 0000000000000080 x4 : 0000000000000001 x3 : 0000000000000000 x2 : ffff0001fefddcd0 x1 : 0000000100000000 x0 : 0000000000000089 Call trace: skb_panic+0x4c/0x50 net/core/skbuff.c:116 skb_over_panic net/core/skbuff.c:125 [inline] skb_put+0xd4/0xdc net/core/skbuff.c:2049 ip6_mc_hdr net/ipv6/mcast.c:1714 [inline] mld_newpack+0x14c/0x270 net/ipv6/mcast.c:1765 add_grhead net/ipv6/mcast.c:1851 [inline] add_grec+0xa20/0xae0 net/ipv6/mcast.c:1989 mld_send_cr+0x438/0x5a8 net/ipv6/mcast.c:2115 mld_ifc_work+0x38/0x290 net/ipv6/mcast.c:2653 process_one_work+0x2d8/0x504 kernel/workqueue.c:2289 worker_thread+0x340/0x610 kernel/workqueue.c:2436 kthread+0x12c/0x158 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860 Code: 91011400 aa0803e1 a90027ea 94373093 (d4210000) Fixes: c12b395a4664 ("gre: Support GRE over IPv6") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20221024020124.3756833-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> [ta: Backport patch for stable kernels < 5.10.y. Fix conflict in net/ipv6/ip6_tunnel.c, mtu initialized with: mtu = rt->dst.dev->mtu - t_hlen;] Cc: <stable@vger.kernel.org> # 4.14.y, 4.19.y, 5.4.y Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d89d7ff01235f218dad37de84457717f699dee79 upstream.

Another syzbot report [1] with no reproducer hints
at a bug in ip6_gre tunnel (dev:ip6gretap0)

Since ipv6 mcast code makes sure to read dev->mtu once
and applies a sanity check on it (see commit b9b312a7a451
"ipv6: mcast: better catch silly mtu values"), a remaining
possibility is that a layer is able to set dev->mtu to
an underflowed value (high order bit set).

This could happen indeed in ip6gre_tnl_link_config_route(),
ip6_tnl_link_config() and ipip6_tunnel_bind_dev()

Make sure to sanitize mtu value in a local variable before
it is written once on dev->mtu, as lockless readers could
catch wrong temporary value.

[1]
skbuff: skb_over_panic: text:ffff80000b7a2f38 len:40 put:40 head:ffff000149dcf200 data:ffff000149dcf2b0 tail:0xd8 end:0xc0 dev:ip6gretap0
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:120
Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 10241 Comm: kworker/1:1 Not tainted 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022
Workqueue: mld mld_ifc_work
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : skb_panic+0x4c/0x50 net/core/skbuff.c:116
lr : skb_panic+0x4c/0x50 net/core/skbuff.c:116
sp : ffff800020dd3b60
x29: ffff800020dd3b70 x28: 0000000000000000 x27: ffff00010df2a800
x26: 00000000000000c0 x25: 00000000000000b0 x24: ffff000149dcf200
x23: 00000000000000c0 x22: 00000000000000d8 x21: ffff80000b7a2f38
x20: ffff00014c2f7800 x19: 0000000000000028 x18: 00000000000001a9
x17: 0000000000000000 x16: ffff80000db49158 x15: ffff000113bf1a80
x14: 0000000000000000 x13: 00000000ffffffff x12: ffff000113bf1a80
x11: ff808000081c0d5c x10: 0000000000000000 x9 : 73f125dc5c63ba00
x8 : 73f125dc5c63ba00 x7 : ffff800008161d1c x6 : 0000000000000000
x5 : 0000000000000080 x4 : 0000000000000001 x3 : 0000000000000000
x2 : ffff0001fefddcd0 x1 : 0000000100000000 x0 : 0000000000000089
Call trace:
skb_panic+0x4c/0x50 net/core/skbuff.c:116
skb_over_panic net/core/skbuff.c:125 [inline]
skb_put+0xd4/0xdc net/core/skbuff.c:2049
ip6_mc_hdr net/ipv6/mcast.c:1714 [inline]
mld_newpack+0x14c/0x270 net/ipv6/mcast.c:1765
add_grhead net/ipv6/mcast.c:1851 [inline]
add_grec+0xa20/0xae0 net/ipv6/mcast.c:1989
mld_send_cr+0x438/0x5a8 net/ipv6/mcast.c:2115
mld_ifc_work+0x38/0x290 net/ipv6/mcast.c:2653
process_one_work+0x2d8/0x504 kernel/workqueue.c:2289
worker_thread+0x340/0x610 kernel/workqueue.c:2436
kthread+0x12c/0x158 kernel/kthread.c:376
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860
Code: 91011400 aa0803e1 a90027ea 94373093 (d4210000)

Fixes: c12b395a4664 ("gre: Support GRE over IPv6")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20221024020124.3756833-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[ta: Backport patch for stable kernels < 5.10.y. Fix conflict in
net/ipv6/ip6_tunnel.c, mtu initialized with:
mtu = rt->dst.dev->mtu - t_hlen;]
Cc: <stable@vger.kernel.org> # 4.14.y, 4.19.y, 5.4.y
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipv6: raw: Deduct extension header length in rawv6_push_pending_frames 2023-01-18T10:42:02+00:00 Herbert Xu herbert@gondor.apana.org.au 2023-01-10T00:59:06+00:00 3998dba0f78a59922b0ef333ccfeb58d9410cd3d commit cb3e9864cdbe35ff6378966660edbcbac955fe17 upstream. The total cork length created by ip6_append_data includes extension headers, so we must exclude them when comparing them against the IPV6_CHECKSUM offset which does not include extension headers. Reported-by: Kyle Zeng <zengyhkyle@gmail.com> Fixes: 357b40a18b04 ("[IPV6]: IPV6_CHECKSUM socket option can corrupt kernel memory") Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit cb3e9864cdbe35ff6378966660edbcbac955fe17 upstream.

The total cork length created by ip6_append_data includes extension
headers, so we must exclude them when comparing them against the
IPV6_CHECKSUM offset which does not include extension headers.

Reported-by: Kyle Zeng <zengyhkyle@gmail.com>
Fixes: 357b40a18b04 ("[IPV6]: IPV6_CHECKSUM socket option can corrupt kernel memory")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipv6: avoid use-after-free in ip6_fragment() 2022-12-14T10:30:48+00:00 Eric Dumazet edumazet@google.com 2022-12-06T10:13:51+00:00 6b6d3be3661bff2746cab26147bd629aa034e094 [ Upstream commit 803e84867de59a1e5d126666d25eb4860cfd2ebe ] Blamed commit claimed rcu_read_lock() was held by ip6_fragment() callers. It seems to not be always true, at least for UDP stack. syzbot reported: BUG: KASAN: use-after-free in ip6_dst_idev include/net/ip6_fib.h:245 [inline] BUG: KASAN: use-after-free in ip6_fragment+0x2724/0x2770 net/ipv6/ip6_output.c:951 Read of size 8 at addr ffff88801d403e80 by task syz-executor.3/7618 CPU: 1 PID: 7618 Comm: syz-executor.3 Not tainted 6.1.0-rc6-syzkaller-00012-g4312098baf37 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x15e/0x45d mm/kasan/report.c:395 kasan_report+0xbf/0x1f0 mm/kasan/report.c:495 ip6_dst_idev include/net/ip6_fib.h:245 [inline] ip6_fragment+0x2724/0x2770 net/ipv6/ip6_output.c:951 __ip6_finish_output net/ipv6/ip6_output.c:193 [inline] ip6_finish_output+0x9a3/0x1170 net/ipv6/ip6_output.c:206 NF_HOOK_COND include/linux/netfilter.h:291 [inline] ip6_output+0x1f1/0x540 net/ipv6/ip6_output.c:227 dst_output include/net/dst.h:445 [inline] ip6_local_out+0xb3/0x1a0 net/ipv6/output_core.c:161 ip6_send_skb+0xbb/0x340 net/ipv6/ip6_output.c:1966 udp_v6_send_skb+0x82a/0x18a0 net/ipv6/udp.c:1286 udp_v6_push_pending_frames+0x140/0x200 net/ipv6/udp.c:1313 udpv6_sendmsg+0x18da/0x2c80 net/ipv6/udp.c:1606 inet6_sendmsg+0x9d/0xe0 net/ipv6/af_inet6.c:665 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xd3/0x120 net/socket.c:734 sock_write_iter+0x295/0x3d0 net/socket.c:1108 call_write_iter include/linux/fs.h:2191 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x9ed/0xdd0 fs/read_write.c:584 ksys_write+0x1ec/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fde3588c0d9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fde365b6168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fde359ac050 RCX: 00007fde3588c0d9 RDX: 000000000000ffdc RSI: 00000000200000c0 RDI: 000000000000000a RBP: 00007fde358e7ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fde35acfb1f R14: 00007fde365b6300 R15: 0000000000022000 </TASK> Allocated by task 7618: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 __kasan_slab_alloc+0x82/0x90 mm/kasan/common.c:325 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slab.h:737 [inline] slab_alloc_node mm/slub.c:3398 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc+0x2b4/0x3d0 mm/slub.c:3422 dst_alloc+0x14a/0x1f0 net/core/dst.c:92 ip6_dst_alloc+0x32/0xa0 net/ipv6/route.c:344 ip6_rt_pcpu_alloc net/ipv6/route.c:1369 [inline] rt6_make_pcpu_route net/ipv6/route.c:1417 [inline] ip6_pol_route+0x901/0x1190 net/ipv6/route.c:2254 pol_lookup_func include/net/ip6_fib.h:582 [inline] fib6_rule_lookup+0x52e/0x6f0 net/ipv6/fib6_rules.c:121 ip6_route_output_flags_noref+0x2e6/0x380 net/ipv6/route.c:2625 ip6_route_output_flags+0x76/0x320 net/ipv6/route.c:2638 ip6_route_output include/net/ip6_route.h:98 [inline] ip6_dst_lookup_tail+0x5ab/0x1620 net/ipv6/ip6_output.c:1092 ip6_dst_lookup_flow+0x90/0x1d0 net/ipv6/ip6_output.c:1222 ip6_sk_dst_lookup_flow+0x553/0x980 net/ipv6/ip6_output.c:1260 udpv6_sendmsg+0x151d/0x2c80 net/ipv6/udp.c:1554 inet6_sendmsg+0x9d/0xe0 net/ipv6/af_inet6.c:665 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xd3/0x120 net/socket.c:734 __sys_sendto+0x23a/0x340 net/socket.c:2117 __do_sys_sendto net/socket.c:2129 [inline] __se_sys_sendto net/socket.c:2125 [inline] __x64_sys_sendto+0xe1/0x1b0 net/socket.c:2125 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 7599: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2e/0x40 mm/kasan/generic.c:511 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1750 slab_free mm/slub.c:3661 [inline] kmem_cache_free+0xee/0x5c0 mm/slub.c:3683 dst_destroy+0x2ea/0x400 net/core/dst.c:127 rcu_do_batch kernel/rcu/tree.c:2250 [inline] rcu_core+0x81f/0x1980 kernel/rcu/tree.c:2510 __do_softirq+0x1fb/0xadc kernel/softirq.c:571 Last potentially related work creation: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:481 call_rcu+0x9d/0x820 kernel/rcu/tree.c:2798 dst_release net/core/dst.c:177 [inline] dst_release+0x7d/0xe0 net/core/dst.c:167 refdst_drop include/net/dst.h:256 [inline] skb_dst_drop include/net/dst.h:268 [inline] skb_release_head_state+0x250/0x2a0 net/core/skbuff.c:838 skb_release_all net/core/skbuff.c:852 [inline] __kfree_skb net/core/skbuff.c:868 [inline] kfree_skb_reason+0x151/0x4b0 net/core/skbuff.c:891 kfree_skb_list_reason+0x4b/0x70 net/core/skbuff.c:901 kfree_skb_list include/linux/skbuff.h:1227 [inline] ip6_fragment+0x2026/0x2770 net/ipv6/ip6_output.c:949 __ip6_finish_output net/ipv6/ip6_output.c:193 [inline] ip6_finish_output+0x9a3/0x1170 net/ipv6/ip6_output.c:206 NF_HOOK_COND include/linux/netfilter.h:291 [inline] ip6_output+0x1f1/0x540 net/ipv6/ip6_output.c:227 dst_output include/net/dst.h:445 [inline] ip6_local_out+0xb3/0x1a0 net/ipv6/output_core.c:161 ip6_send_skb+0xbb/0x340 net/ipv6/ip6_output.c:1966 udp_v6_send_skb+0x82a/0x18a0 net/ipv6/udp.c:1286 udp_v6_push_pending_frames+0x140/0x200 net/ipv6/udp.c:1313 udpv6_sendmsg+0x18da/0x2c80 net/ipv6/udp.c:1606 inet6_sendmsg+0x9d/0xe0 net/ipv6/af_inet6.c:665 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xd3/0x120 net/socket.c:734 sock_write_iter+0x295/0x3d0 net/socket.c:1108 call_write_iter include/linux/fs.h:2191 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x9ed/0xdd0 fs/read_write.c:584 ksys_write+0x1ec/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Second to last potentially related work creation: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:481 call_rcu+0x9d/0x820 kernel/rcu/tree.c:2798 dst_release net/core/dst.c:177 [inline] dst_release+0x7d/0xe0 net/core/dst.c:167 refdst_drop include/net/dst.h:256 [inline] skb_dst_drop include/net/dst.h:268 [inline] __dev_queue_xmit+0x1b9d/0x3ba0 net/core/dev.c:4211 dev_queue_xmit include/linux/netdevice.h:3008 [inline] neigh_resolve_output net/core/neighbour.c:1552 [inline] neigh_resolve_output+0x51b/0x840 net/core/neighbour.c:1532 neigh_output include/net/neighbour.h:546 [inline] ip6_finish_output2+0x56c/0x1530 net/ipv6/ip6_output.c:134 __ip6_finish_output net/ipv6/ip6_output.c:195 [inline] ip6_finish_output+0x694/0x1170 net/ipv6/ip6_output.c:206 NF_HOOK_COND include/linux/netfilter.h:291 [inline] ip6_output+0x1f1/0x540 net/ipv6/ip6_output.c:227 dst_output include/net/dst.h:445 [inline] NF_HOOK include/linux/netfilter.h:302 [inline] NF_HOOK include/linux/netfilter.h:296 [inline] mld_sendpack+0xa09/0xe70 net/ipv6/mcast.c:1820 mld_send_cr net/ipv6/mcast.c:2121 [inline] mld_ifc_work+0x720/0xdc0 net/ipv6/mcast.c:2653 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289 worker_thread+0x669/0x1090 kernel/workqueue.c:2436 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 The buggy address belongs to the object at ffff88801d403dc0 which belongs to the cache ip6_dst_cache of size 240 The buggy address is located 192 bytes inside of 240-byte region [ffff88801d403dc0, ffff88801d403eb0) The buggy address belongs to the physical page: page:ffffea00007500c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1d403 memcg:ffff888022f49c81 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea0001ef6580 dead000000000002 ffff88814addf640 raw: 0000000000000000 00000000800c000c 00000001ffffffff ffff888022f49c81 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 3719, tgid 3719 (kworker/0:6), ts 136223432244, free_ts 136222971441 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x10b5/0x2d50 mm/page_alloc.c:4288 __alloc_pages+0x1cb/0x5b0 mm/page_alloc.c:5555 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2285 alloc_slab_page mm/slub.c:1794 [inline] allocate_slab+0x213/0x300 mm/slub.c:1939 new_slab mm/slub.c:1992 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3180 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3279 slab_alloc_node mm/slub.c:3364 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc+0x31a/0x3d0 mm/slub.c:3422 dst_alloc+0x14a/0x1f0 net/core/dst.c:92 ip6_dst_alloc+0x32/0xa0 net/ipv6/route.c:344 icmp6_dst_alloc+0x71/0x680 net/ipv6/route.c:3261 mld_sendpack+0x5de/0xe70 net/ipv6/mcast.c:1809 mld_send_cr net/ipv6/mcast.c:2121 [inline] mld_ifc_work+0x720/0xdc0 net/ipv6/mcast.c:2653 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289 worker_thread+0x669/0x1090 kernel/workqueue.c:2436 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1459 [inline] free_pcp_prepare+0x65c/0xd90 mm/page_alloc.c:1509 free_unref_page_prepare mm/page_alloc.c:3387 [inline] free_unref_page+0x1d/0x4d0 mm/page_alloc.c:3483 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2586 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x184/0x210 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x66/0x90 mm/kasan/common.c:302 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slab.h:737 [inline] slab_alloc_node mm/slub.c:3398 [inline] kmem_cache_alloc_node+0x304/0x410 mm/slub.c:3443 __alloc_skb+0x214/0x300 net/core/skbuff.c:497 alloc_skb include/linux/skbuff.h:1267 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1191 [inline] netlink_sendmsg+0x9a6/0xe10 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xd3/0x120 net/socket.c:734 __sys_sendto+0x23a/0x340 net/socket.c:2117 __do_sys_sendto net/socket.c:2129 [inline] __se_sys_sendto net/socket.c:2125 [inline] __x64_sys_sendto+0xe1/0x1b0 net/socket.c:2125 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: 1758fd4688eb ("ipv6: remove unnecessary dst_hold() in ip6_fragment()") Reported-by: syzbot+8c0ac31aa9681abb9e2d@syzkaller.appspotmail.com Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Wei Wang <weiwan@google.com> Cc: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/r/20221206101351.2037285-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 803e84867de59a1e5d126666d25eb4860cfd2ebe ]

Blamed commit claimed rcu_read_lock() was held by ip6_fragment() callers.

It seems to not be always true, at least for UDP stack.

syzbot reported:

BUG: KASAN: use-after-free in ip6_dst_idev include/net/ip6_fib.h:245 [inline]
BUG: KASAN: use-after-free in ip6_fragment+0x2724/0x2770 net/ipv6/ip6_output.c:951
Read of size 8 at addr ffff88801d403e80 by task syz-executor.3/7618

CPU: 1 PID: 7618 Comm: syz-executor.3 Not tainted 6.1.0-rc6-syzkaller-00012-g4312098baf37 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:284 [inline]
 print_report+0x15e/0x45d mm/kasan/report.c:395
 kasan_report+0xbf/0x1f0 mm/kasan/report.c:495
 ip6_dst_idev include/net/ip6_fib.h:245 [inline]
 ip6_fragment+0x2724/0x2770 net/ipv6/ip6_output.c:951
 __ip6_finish_output net/ipv6/ip6_output.c:193 [inline]
 ip6_finish_output+0x9a3/0x1170 net/ipv6/ip6_output.c:206
 NF_HOOK_COND include/linux/netfilter.h:291 [inline]
 ip6_output+0x1f1/0x540 net/ipv6/ip6_output.c:227
 dst_output include/net/dst.h:445 [inline]
 ip6_local_out+0xb3/0x1a0 net/ipv6/output_core.c:161
 ip6_send_skb+0xbb/0x340 net/ipv6/ip6_output.c:1966
 udp_v6_send_skb+0x82a/0x18a0 net/ipv6/udp.c:1286
 udp_v6_push_pending_frames+0x140/0x200 net/ipv6/udp.c:1313
 udpv6_sendmsg+0x18da/0x2c80 net/ipv6/udp.c:1606
 inet6_sendmsg+0x9d/0xe0 net/ipv6/af_inet6.c:665
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg+0xd3/0x120 net/socket.c:734
 sock_write_iter+0x295/0x3d0 net/socket.c:1108
 call_write_iter include/linux/fs.h:2191 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x9ed/0xdd0 fs/read_write.c:584
 ksys_write+0x1ec/0x250 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fde3588c0d9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fde365b6168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fde359ac050 RCX: 00007fde3588c0d9
RDX: 000000000000ffdc RSI: 00000000200000c0 RDI: 000000000000000a
RBP: 00007fde358e7ae9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fde35acfb1f R14: 00007fde365b6300 R15: 0000000000022000
 </TASK>

Allocated by task 7618:
 kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 mm/kasan/common.c:52
 __kasan_slab_alloc+0x82/0x90 mm/kasan/common.c:325
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slab.h:737 [inline]
 slab_alloc_node mm/slub.c:3398 [inline]
 slab_alloc mm/slub.c:3406 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3413 [inline]
 kmem_cache_alloc+0x2b4/0x3d0 mm/slub.c:3422
 dst_alloc+0x14a/0x1f0 net/core/dst.c:92
 ip6_dst_alloc+0x32/0xa0 net/ipv6/route.c:344
 ip6_rt_pcpu_alloc net/ipv6/route.c:1369 [inline]
 rt6_make_pcpu_route net/ipv6/route.c:1417 [inline]
 ip6_pol_route+0x901/0x1190 net/ipv6/route.c:2254
 pol_lookup_func include/net/ip6_fib.h:582 [inline]
 fib6_rule_lookup+0x52e/0x6f0 net/ipv6/fib6_rules.c:121
 ip6_route_output_flags_noref+0x2e6/0x380 net/ipv6/route.c:2625
 ip6_route_output_flags+0x76/0x320 net/ipv6/route.c:2638
 ip6_route_output include/net/ip6_route.h:98 [inline]
 ip6_dst_lookup_tail+0x5ab/0x1620 net/ipv6/ip6_output.c:1092
 ip6_dst_lookup_flow+0x90/0x1d0 net/ipv6/ip6_output.c:1222
 ip6_sk_dst_lookup_flow+0x553/0x980 net/ipv6/ip6_output.c:1260
 udpv6_sendmsg+0x151d/0x2c80 net/ipv6/udp.c:1554
 inet6_sendmsg+0x9d/0xe0 net/ipv6/af_inet6.c:665
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg+0xd3/0x120 net/socket.c:734
 __sys_sendto+0x23a/0x340 net/socket.c:2117
 __do_sys_sendto net/socket.c:2129 [inline]
 __se_sys_sendto net/socket.c:2125 [inline]
 __x64_sys_sendto+0xe1/0x1b0 net/socket.c:2125
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Freed by task 7599:
 kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 mm/kasan/common.c:52
 kasan_save_free_info+0x2e/0x40 mm/kasan/generic.c:511
 ____kasan_slab_free mm/kasan/common.c:236 [inline]
 ____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200
 kasan_slab_free include/linux/kasan.h:177 [inline]
 slab_free_hook mm/slub.c:1724 [inline]
 slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1750
 slab_free mm/slub.c:3661 [inline]
 kmem_cache_free+0xee/0x5c0 mm/slub.c:3683
 dst_destroy+0x2ea/0x400 net/core/dst.c:127
 rcu_do_batch kernel/rcu/tree.c:2250 [inline]
 rcu_core+0x81f/0x1980 kernel/rcu/tree.c:2510
 __do_softirq+0x1fb/0xadc kernel/softirq.c:571

Last potentially related work creation:
 kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:481
 call_rcu+0x9d/0x820 kernel/rcu/tree.c:2798
 dst_release net/core/dst.c:177 [inline]
 dst_release+0x7d/0xe0 net/core/dst.c:167
 refdst_drop include/net/dst.h:256 [inline]
 skb_dst_drop include/net/dst.h:268 [inline]
 skb_release_head_state+0x250/0x2a0 net/core/skbuff.c:838
 skb_release_all net/core/skbuff.c:852 [inline]
 __kfree_skb net/core/skbuff.c:868 [inline]
 kfree_skb_reason+0x151/0x4b0 net/core/skbuff.c:891
 kfree_skb_list_reason+0x4b/0x70 net/core/skbuff.c:901
 kfree_skb_list include/linux/skbuff.h:1227 [inline]
 ip6_fragment+0x2026/0x2770 net/ipv6/ip6_output.c:949
 __ip6_finish_output net/ipv6/ip6_output.c:193 [inline]
 ip6_finish_output+0x9a3/0x1170 net/ipv6/ip6_output.c:206
 NF_HOOK_COND include/linux/netfilter.h:291 [inline]
 ip6_output+0x1f1/0x540 net/ipv6/ip6_output.c:227
 dst_output include/net/dst.h:445 [inline]
 ip6_local_out+0xb3/0x1a0 net/ipv6/output_core.c:161
 ip6_send_skb+0xbb/0x340 net/ipv6/ip6_output.c:1966
 udp_v6_send_skb+0x82a/0x18a0 net/ipv6/udp.c:1286
 udp_v6_push_pending_frames+0x140/0x200 net/ipv6/udp.c:1313
 udpv6_sendmsg+0x18da/0x2c80 net/ipv6/udp.c:1606
 inet6_sendmsg+0x9d/0xe0 net/ipv6/af_inet6.c:665
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg+0xd3/0x120 net/socket.c:734
 sock_write_iter+0x295/0x3d0 net/socket.c:1108
 call_write_iter include/linux/fs.h:2191 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x9ed/0xdd0 fs/read_write.c:584
 ksys_write+0x1ec/0x250 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Second to last potentially related work creation:
 kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:481
 call_rcu+0x9d/0x820 kernel/rcu/tree.c:2798
 dst_release net/core/dst.c:177 [inline]
 dst_release+0x7d/0xe0 net/core/dst.c:167
 refdst_drop include/net/dst.h:256 [inline]
 skb_dst_drop include/net/dst.h:268 [inline]
 __dev_queue_xmit+0x1b9d/0x3ba0 net/core/dev.c:4211
 dev_queue_xmit include/linux/netdevice.h:3008 [inline]
 neigh_resolve_output net/core/neighbour.c:1552 [inline]
 neigh_resolve_output+0x51b/0x840 net/core/neighbour.c:1532
 neigh_output include/net/neighbour.h:546 [inline]
 ip6_finish_output2+0x56c/0x1530 net/ipv6/ip6_output.c:134
 __ip6_finish_output net/ipv6/ip6_output.c:195 [inline]
 ip6_finish_output+0x694/0x1170 net/ipv6/ip6_output.c:206
 NF_HOOK_COND include/linux/netfilter.h:291 [inline]
 ip6_output+0x1f1/0x540 net/ipv6/ip6_output.c:227
 dst_output include/net/dst.h:445 [inline]
 NF_HOOK include/linux/netfilter.h:302 [inline]
 NF_HOOK include/linux/netfilter.h:296 [inline]
 mld_sendpack+0xa09/0xe70 net/ipv6/mcast.c:1820
 mld_send_cr net/ipv6/mcast.c:2121 [inline]
 mld_ifc_work+0x720/0xdc0 net/ipv6/mcast.c:2653
 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289
 worker_thread+0x669/0x1090 kernel/workqueue.c:2436
 kthread+0x2e8/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306

The buggy address belongs to the object at ffff88801d403dc0
 which belongs to the cache ip6_dst_cache of size 240
The buggy address is located 192 bytes inside of
 240-byte region [ffff88801d403dc0, ffff88801d403eb0)

The buggy address belongs to the physical page:
page:ffffea00007500c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1d403
memcg:ffff888022f49c81
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea0001ef6580 dead000000000002 ffff88814addf640
raw: 0000000000000000 00000000800c000c 00000001ffffffff ffff888022f49c81
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 3719, tgid 3719 (kworker/0:6), ts 136223432244, free_ts 136222971441
 prep_new_page mm/page_alloc.c:2539 [inline]
 get_page_from_freelist+0x10b5/0x2d50 mm/page_alloc.c:4288
 __alloc_pages+0x1cb/0x5b0 mm/page_alloc.c:5555
 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2285
 alloc_slab_page mm/slub.c:1794 [inline]
 allocate_slab+0x213/0x300 mm/slub.c:1939
 new_slab mm/slub.c:1992 [inline]
 ___slab_alloc+0xa91/0x1400 mm/slub.c:3180
 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3279
 slab_alloc_node mm/slub.c:3364 [inline]
 slab_alloc mm/slub.c:3406 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3413 [inline]
 kmem_cache_alloc+0x31a/0x3d0 mm/slub.c:3422
 dst_alloc+0x14a/0x1f0 net/core/dst.c:92
 ip6_dst_alloc+0x32/0xa0 net/ipv6/route.c:344
 icmp6_dst_alloc+0x71/0x680 net/ipv6/route.c:3261
 mld_sendpack+0x5de/0xe70 net/ipv6/mcast.c:1809
 mld_send_cr net/ipv6/mcast.c:2121 [inline]
 mld_ifc_work+0x720/0xdc0 net/ipv6/mcast.c:2653
 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289
 worker_thread+0x669/0x1090 kernel/workqueue.c:2436
 kthread+0x2e8/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1459 [inline]
 free_pcp_prepare+0x65c/0xd90 mm/page_alloc.c:1509
 free_unref_page_prepare mm/page_alloc.c:3387 [inline]
 free_unref_page+0x1d/0x4d0 mm/page_alloc.c:3483
 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2586
 qlink_free mm/kasan/quarantine.c:168 [inline]
 qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187
 kasan_quarantine_reduce+0x184/0x210 mm/kasan/quarantine.c:294
 __kasan_slab_alloc+0x66/0x90 mm/kasan/common.c:302
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slab.h:737 [inline]
 slab_alloc_node mm/slub.c:3398 [inline]
 kmem_cache_alloc_node+0x304/0x410 mm/slub.c:3443
 __alloc_skb+0x214/0x300 net/core/skbuff.c:497
 alloc_skb include/linux/skbuff.h:1267 [inline]
 netlink_alloc_large_skb net/netlink/af_netlink.c:1191 [inline]
 netlink_sendmsg+0x9a6/0xe10 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg+0xd3/0x120 net/socket.c:734
 __sys_sendto+0x23a/0x340 net/socket.c:2117
 __do_sys_sendto net/socket.c:2129 [inline]
 __se_sys_sendto net/socket.c:2125 [inline]
 __x64_sys_sendto+0xe1/0x1b0 net/socket.c:2125
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fixes: 1758fd4688eb ("ipv6: remove unnecessary dst_hold() in ip6_fragment()")
Reported-by: syzbot+8c0ac31aa9681abb9e2d@syzkaller.appspotmail.com
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Wei Wang <weiwan@google.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20221206101351.2037285-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
dccp/tcp: Reset saddr on failure after inet6?_hash_connect(). 2022-12-08T10:22:59+00:00 Kuniyuki Iwashima kuniyu@amazon.com 2022-11-19T01:49:11+00:00 9d1264c914d3f86a3539856fb123044ba577eedb [ Upstream commit 77934dc6db0d2b111a8f2759e9ad2fb67f5cffa5 ] When connect() is called on a socket bound to the wildcard address, we change the socket's saddr to a local address. If the socket fails to connect() to the destination, we have to reset the saddr. However, when an error occurs after inet_hash6?_connect() in (dccp|tcp)_v[46]_conect(), we forget to reset saddr and leave the socket bound to the address. From the user's point of view, whether saddr is reset or not varies with errno. Let's fix this inconsistent behaviour. Note that after this patch, the repro [0] will trigger the WARN_ON() in inet_csk_get_port() again, but this patch is not buggy and rather fixes a bug papering over the bhash2's bug for which we need another fix. For the record, the repro causes -EADDRNOTAVAIL in inet_hash6_connect() by this sequence: s1 = socket() s1.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1) s1.bind(('127.0.0.1', 10000)) s1.sendto(b'hello', MSG_FASTOPEN, (('127.0.0.1', 10000))) # or s1.connect(('127.0.0.1', 10000)) s2 = socket() s2.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1) s2.bind(('0.0.0.0', 10000)) s2.connect(('127.0.0.1', 10000)) # -EADDRNOTAVAIL s2.listen(32) # WARN_ON(inet_csk(sk)->icsk_bind2_hash != tb2); [0]: https://syzkaller.appspot.com/bug?extid=015d756bbd1f8b5c8f09 Fixes: 3df80d9320bc ("[DCCP]: Introduce DCCPv6") Fixes: 7c657876b63c ("[DCCP]: Initial implementation") Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Joanne Koong <joannelkoong@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 77934dc6db0d2b111a8f2759e9ad2fb67f5cffa5 ]

When connect() is called on a socket bound to the wildcard address,
we change the socket's saddr to a local address.  If the socket
fails to connect() to the destination, we have to reset the saddr.

However, when an error occurs after inet_hash6?_connect() in
(dccp|tcp)_v[46]_conect(), we forget to reset saddr and leave
the socket bound to the address.

From the user's point of view, whether saddr is reset or not varies
with errno.  Let's fix this inconsistent behaviour.

Note that after this patch, the repro [0] will trigger the WARN_ON()
in inet_csk_get_port() again, but this patch is not buggy and rather
fixes a bug papering over the bhash2's bug for which we need another
fix.

For the record, the repro causes -EADDRNOTAVAIL in inet_hash6_connect()
by this sequence:

  s1 = socket()
  s1.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
  s1.bind(('127.0.0.1', 10000))
  s1.sendto(b'hello', MSG_FASTOPEN, (('127.0.0.1', 10000)))
  # or s1.connect(('127.0.0.1', 10000))

  s2 = socket()
  s2.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
  s2.bind(('0.0.0.0', 10000))
  s2.connect(('127.0.0.1', 10000))  # -EADDRNOTAVAIL

  s2.listen(32)  # WARN_ON(inet_csk(sk)->icsk_bind2_hash != tb2);

[0]: https://syzkaller.appspot.com/bug?extid=015d756bbd1f8b5c8f09

Fixes: 3df80d9320bc ("[DCCP]: Introduce DCCPv6")
Fixes: 7c657876b63c ("[DCCP]: Initial implementation")
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Joanne Koong <joannelkoong@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
xfrm: Fix ignored return value in xfrm6_init() 2022-12-08T10:22:58+00:00 Chen Zhongjin chenzhongjin@huawei.com 2022-11-03T09:07:13+00:00 23b83a3c76b3ebf9a447ed848a270fe5d17b713a [ Upstream commit 40781bfb836eda57d19c0baa37c7e72590e05fdc ] When IPv6 module initializing in xfrm6_init(), register_pernet_subsys() is possible to fail but its return value is ignored. If IPv6 initialization fails later and xfrm6_fini() is called, removing uninitialized list in xfrm6_net_ops will cause null-ptr-deref: KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 1 PID: 330 Comm: insmod RIP: 0010:unregister_pernet_operations+0xc9/0x450 Call Trace: <TASK> unregister_pernet_subsys+0x31/0x3e xfrm6_fini+0x16/0x30 [ipv6] ip6_route_init+0xcd/0x128 [ipv6] inet6_init+0x29c/0x602 [ipv6] ... Fix it by catching the error return value of register_pernet_subsys(). Fixes: 8d068875caca ("xfrm: make gc_thresh configurable in all namespaces") Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com> Reviewed-by: Leon Romanovsky <leonro@nvidia.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 40781bfb836eda57d19c0baa37c7e72590e05fdc ]

When IPv6 module initializing in xfrm6_init(), register_pernet_subsys()
is possible to fail but its return value is ignored.

If IPv6 initialization fails later and xfrm6_fini() is called,
removing uninitialized list in xfrm6_net_ops will cause null-ptr-deref:

KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 1 PID: 330 Comm: insmod
RIP: 0010:unregister_pernet_operations+0xc9/0x450
Call Trace:
 <TASK>
 unregister_pernet_subsys+0x31/0x3e
 xfrm6_fini+0x16/0x30 [ipv6]
 ip6_route_init+0xcd/0x128 [ipv6]
 inet6_init+0x29c/0x602 [ipv6]
 ...

Fix it by catching the error return value of register_pernet_subsys().

Fixes: 8d068875caca ("xfrm: make gc_thresh configurable in all namespaces")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ipv6: addrlabel: fix infoleak when sending struct ifaddrlblmsg to network 2022-11-25T16:42:05+00:00 Alexander Potapenko glider@google.com 2022-11-04T10:32:16+00:00 58cd7fdc8c1e6c7873acc08f190069fed88d1c12 [ Upstream commit c23fb2c82267638f9d206cb96bb93e1f93ad7828 ] When copying a `struct ifaddrlblmsg` to the network, __ifal_reserved remained uninitialized, resulting in a 1-byte infoleak: BUG: KMSAN: kernel-network-infoleak in __netdev_start_xmit ./include/linux/netdevice.h:4841 __netdev_start_xmit ./include/linux/netdevice.h:4841 netdev_start_xmit ./include/linux/netdevice.h:4857 xmit_one net/core/dev.c:3590 dev_hard_start_xmit+0x1dc/0x800 net/core/dev.c:3606 __dev_queue_xmit+0x17e8/0x4350 net/core/dev.c:4256 dev_queue_xmit ./include/linux/netdevice.h:3009 __netlink_deliver_tap_skb net/netlink/af_netlink.c:307 __netlink_deliver_tap+0x728/0xad0 net/netlink/af_netlink.c:325 netlink_deliver_tap net/netlink/af_netlink.c:338 __netlink_sendskb net/netlink/af_netlink.c:1263 netlink_sendskb+0x1d9/0x200 net/netlink/af_netlink.c:1272 netlink_unicast+0x56d/0xf50 net/netlink/af_netlink.c:1360 nlmsg_unicast ./include/net/netlink.h:1061 rtnl_unicast+0x5a/0x80 net/core/rtnetlink.c:758 ip6addrlbl_get+0xfad/0x10f0 net/ipv6/addrlabel.c:628 rtnetlink_rcv_msg+0xb33/0x1570 net/core/rtnetlink.c:6082 ... Uninit was created at: slab_post_alloc_hook+0x118/0xb00 mm/slab.h:742 slab_alloc_node mm/slub.c:3398 __kmem_cache_alloc_node+0x4f2/0x930 mm/slub.c:3437 __do_kmalloc_node mm/slab_common.c:954 __kmalloc_node_track_caller+0x117/0x3d0 mm/slab_common.c:975 kmalloc_reserve net/core/skbuff.c:437 __alloc_skb+0x27a/0xab0 net/core/skbuff.c:509 alloc_skb ./include/linux/skbuff.h:1267 nlmsg_new ./include/net/netlink.h:964 ip6addrlbl_get+0x490/0x10f0 net/ipv6/addrlabel.c:608 rtnetlink_rcv_msg+0xb33/0x1570 net/core/rtnetlink.c:6082 netlink_rcv_skb+0x299/0x550 net/netlink/af_netlink.c:2540 rtnetlink_rcv+0x26/0x30 net/core/rtnetlink.c:6109 netlink_unicast_kernel net/netlink/af_netlink.c:1319 netlink_unicast+0x9ab/0xf50 net/netlink/af_netlink.c:1345 netlink_sendmsg+0xebc/0x10f0 net/netlink/af_netlink.c:1921 ... This patch ensures that the reserved field is always initialized. Reported-by: syzbot+3553517af6020c4f2813f1003fe76ef3cbffe98d@syzkaller.appspotmail.com Fixes: 2a8cc6c89039 ("[IPV6] ADDRCONF: Support RFC3484 configurable address selection policy table.") Signed-off-by: Alexander Potapenko <glider@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit c23fb2c82267638f9d206cb96bb93e1f93ad7828 ]

When copying a `struct ifaddrlblmsg` to the network, __ifal_reserved
remained uninitialized, resulting in a 1-byte infoleak:

  BUG: KMSAN: kernel-network-infoleak in __netdev_start_xmit ./include/linux/netdevice.h:4841
   __netdev_start_xmit ./include/linux/netdevice.h:4841
   netdev_start_xmit ./include/linux/netdevice.h:4857
   xmit_one net/core/dev.c:3590
   dev_hard_start_xmit+0x1dc/0x800 net/core/dev.c:3606
   __dev_queue_xmit+0x17e8/0x4350 net/core/dev.c:4256
   dev_queue_xmit ./include/linux/netdevice.h:3009
   __netlink_deliver_tap_skb net/netlink/af_netlink.c:307
   __netlink_deliver_tap+0x728/0xad0 net/netlink/af_netlink.c:325
   netlink_deliver_tap net/netlink/af_netlink.c:338
   __netlink_sendskb net/netlink/af_netlink.c:1263
   netlink_sendskb+0x1d9/0x200 net/netlink/af_netlink.c:1272
   netlink_unicast+0x56d/0xf50 net/netlink/af_netlink.c:1360
   nlmsg_unicast ./include/net/netlink.h:1061
   rtnl_unicast+0x5a/0x80 net/core/rtnetlink.c:758
   ip6addrlbl_get+0xfad/0x10f0 net/ipv6/addrlabel.c:628
   rtnetlink_rcv_msg+0xb33/0x1570 net/core/rtnetlink.c:6082
  ...
  Uninit was created at:
   slab_post_alloc_hook+0x118/0xb00 mm/slab.h:742
   slab_alloc_node mm/slub.c:3398
   __kmem_cache_alloc_node+0x4f2/0x930 mm/slub.c:3437
   __do_kmalloc_node mm/slab_common.c:954
   __kmalloc_node_track_caller+0x117/0x3d0 mm/slab_common.c:975
   kmalloc_reserve net/core/skbuff.c:437
   __alloc_skb+0x27a/0xab0 net/core/skbuff.c:509
   alloc_skb ./include/linux/skbuff.h:1267
   nlmsg_new ./include/net/netlink.h:964
   ip6addrlbl_get+0x490/0x10f0 net/ipv6/addrlabel.c:608
   rtnetlink_rcv_msg+0xb33/0x1570 net/core/rtnetlink.c:6082
   netlink_rcv_skb+0x299/0x550 net/netlink/af_netlink.c:2540
   rtnetlink_rcv+0x26/0x30 net/core/rtnetlink.c:6109
   netlink_unicast_kernel net/netlink/af_netlink.c:1319
   netlink_unicast+0x9ab/0xf50 net/netlink/af_netlink.c:1345
   netlink_sendmsg+0xebc/0x10f0 net/netlink/af_netlink.c:1921
  ...

This patch ensures that the reserved field is always initialized.

Reported-by: syzbot+3553517af6020c4f2813f1003fe76ef3cbffe98d@syzkaller.appspotmail.com
Fixes: 2a8cc6c89039 ("[IPV6] ADDRCONF: Support RFC3484 configurable address selection policy table.")
Signed-off-by: Alexander Potapenko <glider@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
tcp/udp: Make early_demux back namespacified. 2022-11-10T16:57:55+00:00 Kuniyuki Iwashima kuniyu@amazon.com 2022-07-13T17:52:07+00:00 fe3da74428bff06e04214d2478e505ab60987a99 commit 11052589cf5c0bab3b4884d423d5f60c38fcf25d upstream. Commit e21145a9871a ("ipv4: namespacify ip_early_demux sysctl knob") made it possible to enable/disable early_demux on a per-netns basis. Then, we introduced two knobs, tcp_early_demux and udp_early_demux, to switch it for TCP/UDP in commit dddb64bcb346 ("net: Add sysctl to toggle early demux for tcp and udp"). However, the .proc_handler() was wrong and actually disabled us from changing the behaviour in each netns. We can execute early_demux if net.ipv4.ip_early_demux is on and each proto .early_demux() handler is not NULL. When we toggle (tcp|udp)_early_demux, the change itself is saved in each netns variable, but the .early_demux() handler is a global variable, so the handler is switched based on the init_net's sysctl variable. Thus, netns (tcp|udp)_early_demux knobs have nothing to do with the logic. Whether we CAN execute proto .early_demux() is always decided by init_net's sysctl knob, and whether we DO it or not is by each netns ip_early_demux knob. This patch namespacifies (tcp|udp)_early_demux again. For now, the users of the .early_demux() handler are TCP and UDP only, and they are called directly to avoid retpoline. So, we can remove the .early_demux() handler from inet6?_protos and need not dereference them in ip6?_rcv_finish_core(). If another proto needs .early_demux(), we can restore it at that time. Fixes: dddb64bcb346 ("net: Add sysctl to toggle early demux for tcp and udp") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20220713175207.7727-1-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 11052589cf5c0bab3b4884d423d5f60c38fcf25d upstream.

Commit e21145a9871a ("ipv4: namespacify ip_early_demux sysctl knob") made
it possible to enable/disable early_demux on a per-netns basis.  Then, we
introduced two knobs, tcp_early_demux and udp_early_demux, to switch it for
TCP/UDP in commit dddb64bcb346 ("net: Add sysctl to toggle early demux for
tcp and udp").  However, the .proc_handler() was wrong and actually
disabled us from changing the behaviour in each netns.

We can execute early_demux if net.ipv4.ip_early_demux is on and each proto
.early_demux() handler is not NULL.  When we toggle (tcp|udp)_early_demux,
the change itself is saved in each netns variable, but the .early_demux()
handler is a global variable, so the handler is switched based on the
init_net's sysctl variable.  Thus, netns (tcp|udp)_early_demux knobs have
nothing to do with the logic.  Whether we CAN execute proto .early_demux()
is always decided by init_net's sysctl knob, and whether we DO it or not is
by each netns ip_early_demux knob.

This patch namespacifies (tcp|udp)_early_demux again.  For now, the users
of the .early_demux() handler are TCP and UDP only, and they are called
directly to avoid retpoline.  So, we can remove the .early_demux() handler
from inet6?_protos and need not dereference them in ip6?_rcv_finish_core().
If another proto needs .early_demux(), we can restore it at that time.

Fixes: dddb64bcb346 ("net: Add sysctl to toggle early demux for tcp and udp")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20220713175207.7727-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>