linux-stable.git/net/core, branch v5.4.211 Linux kernel stable tree devlink: Fix use-after-free after a failed reload 2022-08-25T09:18:23+00:00 Ido Schimmel idosch@nvidia.com 2022-08-09T11:35:06+00:00 1ad4ba9341f15412cf86dc6addbb73871a10212f commit 6b4db2e528f650c7fb712961aac36455468d5902 upstream. After a failed devlink reload, devlink parameters are still registered, which means user space can set and get their values. In the case of the mlxsw "acl_region_rehash_interval" parameter, these operations will trigger a use-after-free [1]. Fix this by rejecting set and get operations while in the failed state. Return the "-EOPNOTSUPP" error code which does not abort the parameters dump, but instead causes it to skip over the problematic parameter. Another possible fix is to perform these checks in the mlxsw parameter callbacks, but other drivers might be affected by the same problem and I am not aware of scenarios where these stricter checks will cause a regression. [1] mlxsw_spectrum3 0000:00:10.0: Port 125: Failed to register netdev mlxsw_spectrum3 0000:00:10.0: Failed to create ports ================================================================== BUG: KASAN: use-after-free in mlxsw_sp_acl_tcam_vregion_rehash_intrvl_get+0xbd/0xd0 drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c:904 Read of size 4 at addr ffff8880099dcfd8 by task kworker/u4:4/777 CPU: 1 PID: 777 Comm: kworker/u4:4 Not tainted 5.19.0-rc7-custom-126601-gfe26f28c586d #1 Hardware name: QEMU MSN4700, BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 Workqueue: netns cleanup_net Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x92/0xbd lib/dump_stack.c:106 print_address_description mm/kasan/report.c:313 [inline] print_report.cold+0x5e/0x5cf mm/kasan/report.c:429 kasan_report+0xb9/0xf0 mm/kasan/report.c:491 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:306 mlxsw_sp_acl_tcam_vregion_rehash_intrvl_get+0xbd/0xd0 drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c:904 mlxsw_sp_acl_region_rehash_intrvl_get+0x49/0x60 drivers/net/ethernet/mellanox/mlxsw/spectrum_acl.c:1106 mlxsw_sp_params_acl_region_rehash_intrvl_get+0x33/0x80 drivers/net/ethernet/mellanox/mlxsw/spectrum.c:3854 devlink_param_get net/core/devlink.c:4981 [inline] devlink_nl_param_fill+0x238/0x12d0 net/core/devlink.c:5089 devlink_param_notify+0xe5/0x230 net/core/devlink.c:5168 devlink_ns_change_notify net/core/devlink.c:4417 [inline] devlink_ns_change_notify net/core/devlink.c:4396 [inline] devlink_reload+0x15f/0x700 net/core/devlink.c:4507 devlink_pernet_pre_exit+0x112/0x1d0 net/core/devlink.c:12272 ops_pre_exit_list net/core/net_namespace.c:152 [inline] cleanup_net+0x494/0xc00 net/core/net_namespace.c:582 process_one_work+0x9fc/0x1710 kernel/workqueue.c:2289 worker_thread+0x675/0x10b0 kernel/workqueue.c:2436 kthread+0x30c/0x3d0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 </TASK> The buggy address belongs to the physical page: page:ffffea0000267700 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x99dc flags: 0x100000000000000(node=0|zone=1) raw: 0100000000000000 0000000000000000 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880099dce80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8880099dcf00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff8880099dcf80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8880099dd000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8880099dd080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== Fixes: 98bbf70c1c41 ("mlxsw: spectrum: add "acl_region_rehash_interval" devlink param") Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 6b4db2e528f650c7fb712961aac36455468d5902 upstream.

After a failed devlink reload, devlink parameters are still registered,
which means user space can set and get their values. In the case of the
mlxsw "acl_region_rehash_interval" parameter, these operations will
trigger a use-after-free [1].

Fix this by rejecting set and get operations while in the failed state.
Return the "-EOPNOTSUPP" error code which does not abort the parameters
dump, but instead causes it to skip over the problematic parameter.

Another possible fix is to perform these checks in the mlxsw parameter
callbacks, but other drivers might be affected by the same problem and I
am not aware of scenarios where these stricter checks will cause a
regression.

[1]
mlxsw_spectrum3 0000:00:10.0: Port 125: Failed to register netdev
mlxsw_spectrum3 0000:00:10.0: Failed to create ports

==================================================================
BUG: KASAN: use-after-free in mlxsw_sp_acl_tcam_vregion_rehash_intrvl_get+0xbd/0xd0 drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c:904
Read of size 4 at addr ffff8880099dcfd8 by task kworker/u4:4/777

CPU: 1 PID: 777 Comm: kworker/u4:4 Not tainted 5.19.0-rc7-custom-126601-gfe26f28c586d #1
Hardware name: QEMU MSN4700, BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x92/0xbd lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:313 [inline]
 print_report.cold+0x5e/0x5cf mm/kasan/report.c:429
 kasan_report+0xb9/0xf0 mm/kasan/report.c:491
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:306
 mlxsw_sp_acl_tcam_vregion_rehash_intrvl_get+0xbd/0xd0 drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c:904
 mlxsw_sp_acl_region_rehash_intrvl_get+0x49/0x60 drivers/net/ethernet/mellanox/mlxsw/spectrum_acl.c:1106
 mlxsw_sp_params_acl_region_rehash_intrvl_get+0x33/0x80 drivers/net/ethernet/mellanox/mlxsw/spectrum.c:3854
 devlink_param_get net/core/devlink.c:4981 [inline]
 devlink_nl_param_fill+0x238/0x12d0 net/core/devlink.c:5089
 devlink_param_notify+0xe5/0x230 net/core/devlink.c:5168
 devlink_ns_change_notify net/core/devlink.c:4417 [inline]
 devlink_ns_change_notify net/core/devlink.c:4396 [inline]
 devlink_reload+0x15f/0x700 net/core/devlink.c:4507
 devlink_pernet_pre_exit+0x112/0x1d0 net/core/devlink.c:12272
 ops_pre_exit_list net/core/net_namespace.c:152 [inline]
 cleanup_net+0x494/0xc00 net/core/net_namespace.c:582
 process_one_work+0x9fc/0x1710 kernel/workqueue.c:2289
 worker_thread+0x675/0x10b0 kernel/workqueue.c:2436
 kthread+0x30c/0x3d0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>

The buggy address belongs to the physical page:
page:ffffea0000267700 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x99dc
flags: 0x100000000000000(node=0|zone=1)
raw: 0100000000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880099dce80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880099dcf00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8880099dcf80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                    ^
 ffff8880099dd000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880099dd080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================

Fixes: 98bbf70c1c41 ("mlxsw: spectrum: add "acl_region_rehash_interval" devlink param")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tcp: Fix data-races around sysctl knobs related to SYN option. 2022-07-29T15:14:14+00:00 Kuniyuki Iwashima kuniyu@amazon.com 2022-07-18T17:26:44+00:00 795aee11fda4d73615bc56b9111052f32da64830 [ Upstream commit 3666f666e99600518ab20982af04a078bbdad277 ] While reading these knobs, they can be changed concurrently. Thus, we need to add READ_ONCE() to their readers. - tcp_sack - tcp_window_scaling - tcp_timestamps Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 3666f666e99600518ab20982af04a078bbdad277 ]

While reading these knobs, they can be changed concurrently.
Thus, we need to add READ_ONCE() to their readers.

  - tcp_sack
  - tcp_window_scaling
  - tcp_timestamps

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
tcp: Fix data-races around sysctl_tcp_syncookies. 2022-07-29T15:14:13+00:00 Kuniyuki Iwashima kuniyu@amazon.com 2022-07-15T17:17:47+00:00 b222de2560ab56ca30452d35b7cc0fdd7be98ed2 [ Upstream commit f2e383b5bb6bbc60a0b94b87b3e49a2b1aefd11e ] While reading sysctl_tcp_syncookies, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit f2e383b5bb6bbc60a0b94b87b3e49a2b1aefd11e ]

While reading sysctl_tcp_syncookies, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
seg6: bpf: fix skb checksum in bpf_push_seg6_encap() 2022-07-21T18:59:23+00:00 Andrea Mayer andrea.mayer@uniroma2.it 2022-07-12T17:58:37+00:00 ba60ca0ed12ead60975b9084eec71459733d5005 [ Upstream commit 4889fbd98deaf243c3baadc54e296d71c6af1eb0 ] Both helper functions bpf_lwt_seg6_action() and bpf_lwt_push_encap() use the bpf_push_seg6_encap() to encapsulate the packet in an IPv6 with Segment Routing Header (SRH) or insert an SRH between the IPv6 header and the payload. To achieve this result, such helper functions rely on bpf_push_seg6_encap() which, in turn, leverages seg6_do_srh_{encap,inline}() to perform the required operation (i.e. encap/inline). This patch removes the initialization of the IPv6 header payload length from bpf_push_seg6_encap(), as it is now handled properly by seg6_do_srh_{encap,inline}() to prevent corruption of the skb checksum. Fixes: fe94cc290f53 ("bpf: Add IPv6 Segment Routing helpers") Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 4889fbd98deaf243c3baadc54e296d71c6af1eb0 ]

Both helper functions bpf_lwt_seg6_action() and bpf_lwt_push_encap() use
the bpf_push_seg6_encap() to encapsulate the packet in an IPv6 with Segment
Routing Header (SRH) or insert an SRH between the IPv6 header and the
payload.
To achieve this result, such helper functions rely on bpf_push_seg6_encap()
which, in turn, leverages seg6_do_srh_{encap,inline}() to perform the
required operation (i.e. encap/inline).

This patch removes the initialization of the IPv6 header payload length
from bpf_push_seg6_encap(), as it is now handled properly by
seg6_do_srh_{encap,inline}() to prevent corruption of the skb checksum.

Fixes: fe94cc290f53 ("bpf: Add IPv6 Segment Routing helpers")
Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
bpf: Fix request_sock leak in sk lookup helpers 2022-06-29T06:58:45+00:00 Jon Maxwell jmaxwell37@gmail.com 2022-06-15T01:15:40+00:00 8ffe2e50e9678c8373027492035f094b130437f1 [ Upstream commit 3046a827316c0e55fc563b4fb78c93b9ca5c7c37 ] A customer reported a request_socket leak in a Calico cloud environment. We found that a BPF program was doing a socket lookup with takes a refcnt on the socket and that it was finding the request_socket but returning the parent LISTEN socket via sk_to_full_sk() without decrementing the child request socket 1st, resulting in request_sock slab object leak. This patch retains the existing behaviour of returning full socks to the caller but it also decrements the child request_socket if one is present before doing so to prevent the leak. Thanks to Curtis Taylor for all the help in diagnosing and testing this. And thanks to Antoine Tenart for the reproducer and patch input. v2 of this patch contains, refactor as per Daniel Borkmann's suggestions to validate RCU flags on the listen socket so that it balances with bpf_sk_release() and update comments as per Martin KaFai Lau's suggestion. One small change to Daniels suggestion, put "sk = sk2" under "if (sk2 != sk)" to avoid an extra instruction. Fixes: f7355a6c0497 ("bpf: Check sk_fullsock() before returning from bpf_sk_lookup()") Fixes: edbf8c01de5a ("bpf: add skc_lookup_tcp helper") Co-developed-by: Antoine Tenart <atenart@kernel.org> Signed-off-by: Antoine Tenart <atenart@kernel.org> Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Curtis Taylor <cutaylor-pub@yahoo.com> Cc: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/56d6f898-bde0-bb25-3427-12a330b29fb8@iogearbox.net Link: https://lore.kernel.org/bpf/20220615011540.813025-1-jmaxwell37@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 3046a827316c0e55fc563b4fb78c93b9ca5c7c37 ]

A customer reported a request_socket leak in a Calico cloud environment. We
found that a BPF program was doing a socket lookup with takes a refcnt on
the socket and that it was finding the request_socket but returning the parent
LISTEN socket via sk_to_full_sk() without decrementing the child request socket
1st, resulting in request_sock slab object leak. This patch retains the
existing behaviour of returning full socks to the caller but it also decrements
the child request_socket if one is present before doing so to prevent the leak.

Thanks to Curtis Taylor for all the help in diagnosing and testing this. And
thanks to Antoine Tenart for the reproducer and patch input.

v2 of this patch contains, refactor as per Daniel Borkmann's suggestions to
validate RCU flags on the listen socket so that it balances with bpf_sk_release()
and update comments as per Martin KaFai Lau's suggestion. One small change to
Daniels suggestion, put "sk = sk2" under "if (sk2 != sk)" to avoid an extra
instruction.

Fixes: f7355a6c0497 ("bpf: Check sk_fullsock() before returning from bpf_sk_lookup()")
Fixes: edbf8c01de5a ("bpf: add skc_lookup_tcp helper")
Co-developed-by: Antoine Tenart <atenart@kernel.org>
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Curtis Taylor <cutaylor-pub@yahoo.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/56d6f898-bde0-bb25-3427-12a330b29fb8@iogearbox.net
Link: https://lore.kernel.org/bpf/20220615011540.813025-1-jmaxwell37@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
bpf: Enlarge offset check value to INT_MAX in bpf_skb_{load,store}_bytes 2022-06-06T06:33:51+00:00 Liu Jian liujian56@huawei.com 2022-04-16T10:57:59+00:00 e00c2f22fbfa99260e24b6165504dbc711a35d62 commit 45969b4152c1752089351cd6836a42a566d49bcf upstream. The data length of skb frags + frag_list may be greater than 0xffff, and skb_header_pointer can not handle negative offset. So, here INT_MAX is used to check the validity of offset. Add the same change to the related function skb_store_bytes. Fixes: 05c74e5e53f6 ("bpf: add bpf_skb_load_bytes helper") Signed-off-by: Liu Jian <liujian56@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20220416105801.88708-2-liujian56@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 45969b4152c1752089351cd6836a42a566d49bcf upstream.

The data length of skb frags + frag_list may be greater than 0xffff, and
skb_header_pointer can not handle negative offset. So, here INT_MAX is used
to check the validity of offset. Add the same change to the related function
skb_store_bytes.

Fixes: 05c74e5e53f6 ("bpf: add bpf_skb_load_bytes helper")
Signed-off-by: Liu Jian <liujian56@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20220416105801.88708-2-liujian56@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
secure_seq: use the 64 bits of the siphash for port offset calculation 2022-06-06T06:33:49+00:00 Willy Tarreau w@1wt.eu 2022-05-02T08:46:08+00:00 ab5b00cfe0500f5f5a3648ca945b892156b839fb commit b2d057560b8107c633b39aabe517ff9d93f285e3 upstream. SipHash replaced MD5 in secure_ipv{4,6}_port_ephemeral() via commit 7cd23e5300c1 ("secure_seq: use SipHash in place of MD5"), but the output remained truncated to 32-bit only. In order to exploit more bits from the hash, let's make the functions return the full 64-bit of siphash_3u32(). We also make sure the port offset calculation in __inet_hash_connect() remains done on 32-bit to avoid the need for div_u64_rem() and an extra cost on 32-bit systems. Cc: Jason A. Donenfeld <Jason@zx2c4.com> Cc: Moshe Kol <moshe.kol@mail.huji.ac.il> Cc: Yossi Gilad <yossi.gilad@mail.huji.ac.il> Cc: Amit Klein <aksecurity@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Jakub Kicinski <kuba@kernel.org> [SG: Adjusted context] Signed-off-by: Stefan Ghinea <stefan.ghinea@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit b2d057560b8107c633b39aabe517ff9d93f285e3 upstream.

SipHash replaced MD5 in secure_ipv{4,6}_port_ephemeral() via commit
7cd23e5300c1 ("secure_seq: use SipHash in place of MD5"), but the output
remained truncated to 32-bit only. In order to exploit more bits from the
hash, let's make the functions return the full 64-bit of siphash_3u32().
We also make sure the port offset calculation in __inet_hash_connect()
remains done on 32-bit to avoid the need for div_u64_rem() and an extra
cost on 32-bit systems.

Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Moshe Kol <moshe.kol@mail.huji.ac.il>
Cc: Yossi Gilad <yossi.gilad@mail.huji.ac.il>
Cc: Amit Klein <aksecurity@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[SG: Adjusted context]
Signed-off-by: Stefan Ghinea <stefan.ghinea@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tcp: resalt the secret every 10 seconds 2022-05-18T07:47:26+00:00 Eric Dumazet edumazet@google.com 2022-05-02T08:46:10+00:00 6e34ee5b5b921d25992f54141aaaf9859733863f [ Upstream commit 4dfa9b438ee34caca4e6a4e5e961641807367f6f ] In order to limit the ability for an observer to recognize the source ports sequence used to contact a set of destinations, we should periodically shuffle the secret. 10 seconds looks effective enough without causing particular issues. Cc: Moshe Kol <moshe.kol@mail.huji.ac.il> Cc: Yossi Gilad <yossi.gilad@mail.huji.ac.il> Cc: Amit Klein <aksecurity@gmail.com> Cc: Jason A. Donenfeld <Jason@zx2c4.com> Tested-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 4dfa9b438ee34caca4e6a4e5e961641807367f6f ]

In order to limit the ability for an observer to recognize the source
ports sequence used to contact a set of destinations, we should
periodically shuffle the secret. 10 seconds looks effective enough
without causing particular issues.

Cc: Moshe Kol <moshe.kol@mail.huji.ac.il>
Cc: Yossi Gilad <yossi.gilad@mail.huji.ac.il>
Cc: Amit Klein <aksecurity@gmail.com>
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Tested-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
bpf, lwt: Fix crash when using bpf_skb_set_tunnel_key() from bpf_xmit lwt hook 2022-05-09T07:03:24+00:00 Eyal Birger eyal.birger@gmail.com 2022-04-20T16:52:19+00:00 2b9a13d98dfcc7ab06fd2b09ed010c7164521be7 [ Upstream commit b02d196c44ead1a5949729be9ff08fe781c3e48a ] xmit_check_hhlen() observes the dst for getting the device hard header length to make sure a modified packet can fit. When a helper which changes the dst - such as bpf_skb_set_tunnel_key() - is called as part of the xmit program the accessed dst is no longer valid. This leads to the following splat: BUG: kernel NULL pointer dereference, address: 00000000000000de #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 0 PID: 798 Comm: ping Not tainted 5.18.0-rc2+ #103 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 RIP: 0010:bpf_xmit+0xfb/0x17f Code: c6 c0 4d cd 8e 48 c7 c7 7d 33 f0 8e e8 42 09 fb ff 48 8b 45 58 48 8b 95 c8 00 00 00 48 2b 95 c0 00 00 00 48 83 e0 fe 48 8b 00 <0f> b7 80 de 00 00 00 39 c2 73 22 29 d0 b9 20 0a 00 00 31 d2 48 89 RSP: 0018:ffffb148c0bc7b98 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000240008 RCX: 0000000000000000 RDX: 0000000000000010 RSI: 00000000ffffffea RDI: 00000000ffffffff RBP: ffff922a828a4e00 R08: ffffffff8f1350e8 R09: 00000000ffffdfff R10: ffffffff8f055100 R11: ffffffff8f105100 R12: 0000000000000000 R13: ffff922a828a4e00 R14: 0000000000000040 R15: 0000000000000000 FS: 00007f414e8f0080(0000) GS:ffff922afdc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000000de CR3: 0000000002d80006 CR4: 0000000000370ef0 Call Trace: <TASK> lwtunnel_xmit.cold+0x71/0xc8 ip_finish_output2+0x279/0x520 ? __ip_finish_output.part.0+0x21/0x130 Fix by fetching the device hard header length before running the BPF code. Fixes: 3a0af8fd61f9 ("bpf: BPF for lightweight tunnel infrastructure") Signed-off-by: Eyal Birger <eyal.birger@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20220420165219.1755407-1-eyal.birger@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit b02d196c44ead1a5949729be9ff08fe781c3e48a ]

xmit_check_hhlen() observes the dst for getting the device hard header
length to make sure a modified packet can fit. When a helper which changes
the dst - such as bpf_skb_set_tunnel_key() - is called as part of the
xmit program the accessed dst is no longer valid.

This leads to the following splat:

 BUG: kernel NULL pointer dereference, address: 00000000000000de
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 0 P4D 0
 Oops: 0000 [#1] PREEMPT SMP PTI
 CPU: 0 PID: 798 Comm: ping Not tainted 5.18.0-rc2+ #103
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
 RIP: 0010:bpf_xmit+0xfb/0x17f
 Code: c6 c0 4d cd 8e 48 c7 c7 7d 33 f0 8e e8 42 09 fb ff 48 8b 45 58 48 8b 95 c8 00 00 00 48 2b 95 c0 00 00 00 48 83 e0 fe 48 8b 00 <0f> b7 80 de 00 00 00 39 c2 73 22 29 d0 b9 20 0a 00 00 31 d2 48 89
 RSP: 0018:ffffb148c0bc7b98 EFLAGS: 00010282
 RAX: 0000000000000000 RBX: 0000000000240008 RCX: 0000000000000000
 RDX: 0000000000000010 RSI: 00000000ffffffea RDI: 00000000ffffffff
 RBP: ffff922a828a4e00 R08: ffffffff8f1350e8 R09: 00000000ffffdfff
 R10: ffffffff8f055100 R11: ffffffff8f105100 R12: 0000000000000000
 R13: ffff922a828a4e00 R14: 0000000000000040 R15: 0000000000000000
 FS:  00007f414e8f0080(0000) GS:ffff922afdc00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00000000000000de CR3: 0000000002d80006 CR4: 0000000000370ef0
 Call Trace:
  <TASK>
  lwtunnel_xmit.cold+0x71/0xc8
  ip_finish_output2+0x279/0x520
  ? __ip_finish_output.part.0+0x21/0x130

Fix by fetching the device hard header length before running the BPF code.

Fixes: 3a0af8fd61f9 ("bpf: BPF for lightweight tunnel infrastructure")
Signed-off-by: Eyal Birger <eyal.birger@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220420165219.1755407-1-eyal.birger@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
net/sched: flower: fix parsing of ethertype following VLAN header 2022-04-20T07:19:34+00:00 Vlad Buslov vladbu@nvidia.com 2022-04-06T11:22:41+00:00 5f2e54391893c67b709a64b280417ca0318adb73 [ Upstream commit 2105f700b53c24aa48b65c15652acc386044d26a ] A tc flower filter matching TCA_FLOWER_KEY_VLAN_ETH_TYPE is expected to match the L2 ethertype following the first VLAN header, as confirmed by linked discussion with the maintainer. However, such rule also matches packets that have additional second VLAN header, even though filter has both eth_type and vlan_ethtype set to "ipv4". Looking at the code this seems to be mostly an artifact of the way flower uses flow dissector. First, even though looking at the uAPI eth_type and vlan_ethtype appear like a distinct fields, in flower they are all mapped to the same key->basic.n_proto. Second, flow dissector skips following VLAN header as no keys for FLOW_DISSECTOR_KEY_CVLAN are set and eventually assigns the value of n_proto to last parsed header. With these, such filters ignore any headers present between first VLAN header and first "non magic" header (ipv4 in this case) that doesn't result FLOW_DISSECT_RET_PROTO_AGAIN. Fix the issue by extending flow dissector VLAN key structure with new 'vlan_eth_type' field that matches first ethertype following previously parsed VLAN header. Modify flower classifier to set the new flow_dissector_key_vlan->vlan_eth_type with value obtained from TCA_FLOWER_KEY_VLAN_ETH_TYPE/TCA_FLOWER_KEY_CVLAN_ETH_TYPE uAPIs. Link: https://lore.kernel.org/all/Yjhgi48BpTGh6dig@nanopsycho/ Fixes: 9399ae9a6cb2 ("net_sched: flower: Add vlan support") Fixes: d64efd0926ba ("net/sched: flower: Add supprt for matching on QinQ vlan headers") Signed-off-by: Vlad Buslov <vladbu@nvidia.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 2105f700b53c24aa48b65c15652acc386044d26a ]

A tc flower filter matching TCA_FLOWER_KEY_VLAN_ETH_TYPE is expected to
match the L2 ethertype following the first VLAN header, as confirmed by
linked discussion with the maintainer. However, such rule also matches
packets that have additional second VLAN header, even though filter has
both eth_type and vlan_ethtype set to "ipv4". Looking at the code this
seems to be mostly an artifact of the way flower uses flow dissector.
First, even though looking at the uAPI eth_type and vlan_ethtype appear
like a distinct fields, in flower they are all mapped to the same
key->basic.n_proto. Second, flow dissector skips following VLAN header as
no keys for FLOW_DISSECTOR_KEY_CVLAN are set and eventually assigns the
value of n_proto to last parsed header. With these, such filters ignore any
headers present between first VLAN header and first "non magic"
header (ipv4 in this case) that doesn't result
FLOW_DISSECT_RET_PROTO_AGAIN.

Fix the issue by extending flow dissector VLAN key structure with new
'vlan_eth_type' field that matches first ethertype following previously
parsed VLAN header. Modify flower classifier to set the new
flow_dissector_key_vlan->vlan_eth_type with value obtained from
TCA_FLOWER_KEY_VLAN_ETH_TYPE/TCA_FLOWER_KEY_CVLAN_ETH_TYPE uAPIs.

Link: https://lore.kernel.org/all/Yjhgi48BpTGh6dig@nanopsycho/
Fixes: 9399ae9a6cb2 ("net_sched: flower: Add vlan support")
Fixes: d64efd0926ba ("net/sched: flower: Add supprt for matching on QinQ vlan headers")
Signed-off-by: Vlad Buslov <vladbu@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>