linux-stable.git/net/core, branch v6.10

net: fix rc7's __skb_datagram_iter()

2024-07-09T18:24:54+00:00

X would not start in my old 32-bit partition (and the "n"-handling looks
just as wrong on 64-bit, but for whatever reason did not show up there):
"n" must be accumulated over all pages before it's added to "offset" and
compared with "copy", immediately after the skb_frag_foreach_page() loop.

Fixes: d2d30a376d9c ("net: allow skb_datagram_iter to be called from any context")
Signed-off-by: Hugh Dickins 
Reviewed-by: Sagi Grimberg 
Link: https://patch.msgid.link/fef352e8-b89a-da51-f8ce-04bc39ee6481@google.com
Signed-off-by: Jakub Kicinski

skmsg: Skip zero length skb in sk_msg_recvmsg

2024-07-09T08:24:50+00:00

When running BPF selftests (./test_progs -t sockmap_basic) on a Loongarch
platform, the following kernel panic occurs:

  [...]
  Oops[#1]:
  CPU: 22 PID: 2824 Comm: test_progs Tainted: G           OE  6.10.0-rc2+ #18
  Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018
     ... ...
     ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560
    ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0
   CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
   PRMD: 0000000c (PPLV0 +PIE +PWE)
   EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
   ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
  ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
   BADV: 0000000000000040
   PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)
  Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack
  Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)
  Stack : ...
  Call Trace:
  [<9000000004162774>] copy_page_to_iter+0x74/0x1c0
  [<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560
  [<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0
  [<90000000049aae34>] inet_recvmsg+0x54/0x100
  [<900000000481ad5c>] sock_recvmsg+0x7c/0xe0
  [<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0
  [<900000000481e27c>] sys_recvfrom+0x1c/0x40
  [<9000000004c076ec>] do_syscall+0x8c/0xc0
  [<9000000003731da4>] handle_syscall+0xc4/0x160
  Code: ...
  ---[ end trace 0000000000000000 ]---
  Kernel panic - not syncing: Fatal exception
  Kernel relocated by 0x3510000
   .text @ 0x9000000003710000
   .data @ 0x9000000004d70000
   .bss  @ 0x9000000006469400
  ---[ end Kernel panic - not syncing: Fatal exception ]---
  [...]

This crash happens every time when running sockmap_skb_verdict_shutdown
subtest in sockmap_basic.

This crash is because a NULL pointer is passed to page_address() in the
sk_msg_recvmsg(). Due to the different implementations depending on the
architecture, page_address(NULL) will trigger a panic on Loongarch
platform but not on x86 platform. So this bug was hidden on x86 platform
for a while, but now it is exposed on Loongarch platform. The root cause
is that a zero length skb (skb->len == 0) was put on the queue.

This zero length skb is a TCP FIN packet, which was sent by shutdown(),
invoked in test_sockmap_skb_verdict_shutdown():

	shutdown(p1, SHUT_WR);

In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no
page is put to this sge (see sg_set_page in sg_set_page), but this empty
sge is queued into ingress_msg list.

And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by
sg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it
to kmap_local_page() and to page_address(), then kernel panics.

To solve this, we should skip this zero length skb. So in sk_msg_recvmsg(),
if copy is zero, that means it's a zero length skb, skip invoking
copy_page_to_iter(). We are using the EFAULT return triggered by
copy_page_to_iter to check for is_fin in tcp_bpf.c.

Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface")
Suggested-by: John Fastabend 
Signed-off-by: Geliang Tang 
Signed-off-by: Daniel Borkmann 
Reviewed-by: John Fastabend 
Link: https://lore.kernel.org/bpf/e3a16eacdc6740658ee02a33489b1b9d4912f378.1719992715.git.tanggeliang@kylinos.cn

net: allow skb_datagram_iter to be called from any context

2024-07-02T12:55:15+00:00

We only use the mapping in a single context, so kmap_local is sufficient
and cheaper. Make sure to use skb_frag_foreach_page as skb frags may
contain compound pages and we need to map page by page.

Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-lkp/202406161539.b5ff7b20-oliver.sang@intel.com
Fixes: 950fcaecd5cc ("datagram: consolidate datagram copy to iter helpers")
Signed-off-by: Sagi Grimberg 
Link: https://patch.msgid.link/20240626100008.831849-1-sagi@grimberg.me
Signed-off-by: Paolo Abeni

Merge tag 'for-netdev' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

2024-06-25T01:15:22+00:00

Daniel Borkmann says:

====================
pull-request: bpf 2024-06-24

We've added 12 non-merge commits during the last 10 day(s) which contain
a total of 10 files changed, 412 insertions(+), 16 deletions(-).

The main changes are:

1) Fix a BPF verifier issue validating may_goto with a negative offset,
   from Alexei Starovoitov.

2) Fix a BPF verifier validation bug with may_goto combined with jump to
   the first instruction, also from Alexei Starovoitov.

3) Fix a bug with overrunning reservations in BPF ring buffer,
   from Daniel Borkmann.

4) Fix a bug in BPF verifier due to missing proper var_off setting related
   to movsx instruction, from Yonghong Song.

5) Silence unnecessary syzkaller-triggered warning in __xdp_reg_mem_model(),
   from Daniil Dulov.

* tag 'for-netdev' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  xdp: Remove WARN() from __xdp_reg_mem_model()
  selftests/bpf: Add tests for may_goto with negative offset.
  bpf: Fix may_goto with negative offset.
  selftests/bpf: Add more ring buffer test coverage
  bpf: Fix overrunning reservations in ringbuf
  selftests/bpf: Tests with may_goto and jumps to the 1st insn
  bpf: Fix the corner case with may_goto and jump to the 1st insn.
  bpf: Update BPF LSM maintainer list
  bpf: Fix remap of arena.
  selftests/bpf: Add a few tests to cover
  bpf: Add missed var_off setting in coerce_subreg_to_size_sx()
  bpf: Add missed var_off setting in set_sext32_default_val()
====================

Link: https://patch.msgid.link/20240624124330.8401-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski

xdp: Remove WARN() from __xdp_reg_mem_model()

2024-06-24T11:44:02+00:00

syzkaller reports a warning in __xdp_reg_mem_model().

The warning occurs only if __mem_id_init_hash_table() returns an error. It
returns the error in two cases:

  1. memory allocation fails;
  2. rhashtable_init() fails when some fields of rhashtable_params
     struct are not initialized properly.

The second case cannot happen since there is a static const rhashtable_params
struct with valid fields. So, warning is only triggered when there is a
problem with memory allocation.

Thus, there is no sense in using WARN() to handle this error and it can be
safely removed.

WARNING: CPU: 0 PID: 5065 at net/core/xdp.c:299 __xdp_reg_mem_model+0x2d9/0x650 net/core/xdp.c:299

CPU: 0 PID: 5065 Comm: syz-executor883 Not tainted 6.8.0-syzkaller-05271-gf99c5f563c17 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:__xdp_reg_mem_model+0x2d9/0x650 net/core/xdp.c:299

Call Trace:
 xdp_reg_mem_model+0x22/0x40 net/core/xdp.c:344
 xdp_test_run_setup net/bpf/test_run.c:188 [inline]
 bpf_test_run_xdp_live+0x365/0x1e90 net/bpf/test_run.c:377
 bpf_prog_test_run_xdp+0x813/0x11b0 net/bpf/test_run.c:1267
 bpf_prog_test_run+0x33a/0x3b0 kernel/bpf/syscall.c:4240
 __sys_bpf+0x48d/0x810 kernel/bpf/syscall.c:5649
 __do_sys_bpf kernel/bpf/syscall.c:5738 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5736 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5736
 do_syscall_64+0xfb/0x240
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

Found by Linux Verification Center (linuxtesting.org) with syzkaller.

Fixes: 8d5d88527587 ("xdp: rhashtable with allocator ID to pointer mapping")
Signed-off-by: Daniil Dulov 
Signed-off-by: Daniel Borkmann 
Acked-by: Jesper Dangaard Brouer 
Link: https://lore.kernel.org/all/20240617162708.492159-1-d.dulov@aladdin.ru
Link: https://lore.kernel.org/bpf/20240624080747.36858-1-d.dulov@aladdin.ru

net: add softirq safety to netdev_rename_lock

2024-06-21T11:18:34+00:00

syzbot reported a lockdep violation involving bridge driver [1]

Make sure netdev_rename_lock is softirq safe to fix this issue.

[1]
WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
6.10.0-rc2-syzkaller-00249-gbe27b8965297 #0 Not tainted
   -----------------------------------------------------
syz-executor.2/9449 [HC0[0]:SC0[2]:HE0:SE0] is trying to acquire:
 ffffffff8f5de668 (netdev_rename_lock.seqcount){+.+.}-{0:0}, at: rtnl_fill_ifinfo+0x38e/0x2270 net/core/rtnetlink.c:1839

and this task is already holding:
 ffff888060c64cb8 (&br->lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
 ffff888060c64cb8 (&br->lock){+.-.}-{2:2}, at: br_port_slave_changelink+0x3d/0x150 net/bridge/br_netlink.c:1212
which would create a new lock dependency:
 (&br->lock){+.-.}-{2:2} -> (netdev_rename_lock.seqcount){+.+.}-{0:0}

but this new dependency connects a SOFTIRQ-irq-safe lock:
 (&br->lock){+.-.}-{2:2}

... which became SOFTIRQ-irq-safe at:
   lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
   __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
   _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
   spin_lock include/linux/spinlock.h:351 [inline]
   br_forward_delay_timer_expired+0x50/0x440 net/bridge/br_stp_timer.c:86
   call_timer_fn+0x18e/0x650 kernel/time/timer.c:1792
   expire_timers kernel/time/timer.c:1843 [inline]
   __run_timers kernel/time/timer.c:2417 [inline]
   __run_timer_base+0x66a/0x8e0 kernel/time/timer.c:2428
   run_timer_base kernel/time/timer.c:2437 [inline]
   run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2447
   handle_softirqs+0x2c4/0x970 kernel/softirq.c:554
   __do_softirq kernel/softirq.c:588 [inline]
   invoke_softirq kernel/softirq.c:428 [inline]
   __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637
   irq_exit_rcu+0x9/0x30 kernel/softirq.c:649
   instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
   sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043
   asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
   lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5758
   fs_reclaim_acquire+0xaf/0x140 mm/page_alloc.c:3800
   might_alloc include/linux/sched/mm.h:334 [inline]
   slab_pre_alloc_hook mm/slub.c:3890 [inline]
   slab_alloc_node mm/slub.c:3980 [inline]
   kmalloc_trace_noprof+0x3d/0x2c0 mm/slub.c:4147
   kmalloc_noprof include/linux/slab.h:660 [inline]
   kzalloc_noprof include/linux/slab.h:778 [inline]
   class_dir_create_and_add drivers/base/core.c:3255 [inline]
   get_device_parent+0x2a7/0x410 drivers/base/core.c:3315
   device_add+0x325/0xbf0 drivers/base/core.c:3645
   netdev_register_kobject+0x17e/0x320 net/core/net-sysfs.c:2136
   register_netdevice+0x11d5/0x19e0 net/core/dev.c:10375
   nsim_init_netdevsim drivers/net/netdevsim/netdev.c:690 [inline]
   nsim_create+0x647/0x890 drivers/net/netdevsim/netdev.c:750
   __nsim_dev_port_add+0x6c0/0xae0 drivers/net/netdevsim/dev.c:1390
   nsim_dev_port_add_all drivers/net/netdevsim/dev.c:1446 [inline]
   nsim_dev_reload_create drivers/net/netdevsim/dev.c:1498 [inline]
   nsim_dev_reload_up+0x69b/0x8e0 drivers/net/netdevsim/dev.c:985
   devlink_reload+0x478/0x870 net/devlink/dev.c:474
   devlink_nl_reload_doit+0xbd6/0xe50 net/devlink/dev.c:586
   genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline]
   genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
   genl_rcv_msg+0xb14/0xec0 net/netlink/genetlink.c:1210
   netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2564
   genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
   netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
   netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1361
   netlink_sendmsg+0x8db/0xcb0 net/netlink/af_netlink.c:1905
   sock_sendmsg_nosec net/socket.c:730 [inline]
   __sock_sendmsg+0x221/0x270 net/socket.c:745
   ____sys_sendmsg+0x525/0x7d0 net/socket.c:2585
   ___sys_sendmsg net/socket.c:2639 [inline]
   __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2668
   do_syscall_x64 arch/x86/entry/common.c:52 [inline]
   do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
  entry_SYSCALL_64_after_hwframe+0x77/0x7f

to a SOFTIRQ-irq-unsafe lock:
 (netdev_rename_lock.seqcount){+.+.}-{0:0}

... which became SOFTIRQ-irq-unsafe at:
...
   lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
   do_write_seqcount_begin_nested include/linux/seqlock.h:469 [inline]
   do_write_seqcount_begin include/linux/seqlock.h:495 [inline]
   write_seqlock include/linux/seqlock.h:823 [inline]
   dev_change_name+0x184/0x920 net/core/dev.c:1229
   do_setlink+0xa4b/0x41f0 net/core/rtnetlink.c:2880
   __rtnl_newlink net/core/rtnetlink.c:3696 [inline]
   rtnl_newlink+0x180b/0x20a0 net/core/rtnetlink.c:3743
   rtnetlink_rcv_msg+0x89b/0x1180 net/core/rtnetlink.c:6635
   netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2564
   netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
   netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1361
   netlink_sendmsg+0x8db/0xcb0 net/netlink/af_netlink.c:1905
   sock_sendmsg_nosec net/socket.c:730 [inline]
   __sock_sendmsg+0x221/0x270 net/socket.c:745
   __sys_sendto+0x3a4/0x4f0 net/socket.c:2192
   __do_sys_sendto net/socket.c:2204 [inline]
   __se_sys_sendto net/socket.c:2200 [inline]
   __x64_sys_sendto+0xde/0x100 net/socket.c:2200
   do_syscall_x64 arch/x86/entry/common.c:52 [inline]
   do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
  entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

 Possible interrupt unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(netdev_rename_lock.seqcount);
                               local_irq_disable();
                               lock(&br->lock);
                               lock(netdev_rename_lock.seqcount);
  
    lock(&br->lock);

 *** DEADLOCK ***

3 locks held by syz-executor.2/9449:
  #0: ffffffff8f5e7448 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
  #0: ffffffff8f5e7448 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x842/0x1180 net/core/rtnetlink.c:6632
  #1: ffff888060c64cb8 (&br->lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
  #1: ffff888060c64cb8 (&br->lock){+.-.}-{2:2}, at: br_port_slave_changelink+0x3d/0x150 net/bridge/br_netlink.c:1212
  #2: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
  #2: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
  #2: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: team_change_rx_flags+0x29/0x330 drivers/net/team/team_core.c:1767

the dependencies between SOFTIRQ-irq-safe lock and the holding lock:
-> (&br->lock){+.-.}-{2:2} {
   HARDIRQ-ON-W at:
                     lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
                     __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
                     _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
                     spin_lock_bh include/linux/spinlock.h:356 [inline]
                     br_add_if+0xb34/0xef0 net/bridge/br_if.c:682
                     do_set_master net/core/rtnetlink.c:2701 [inline]
                     do_setlink+0xe70/0x41f0 net/core/rtnetlink.c:2907
                     __rtnl_newlink net/core/rtnetlink.c:3696 [inline]
                     rtnl_newlink+0x180b/0x20a0 net/core/rtnetlink.c:3743
                     rtnetlink_rcv_msg+0x89b/0x1180 net/core/rtnetlink.c:6635
                     netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2564
                     netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
                     netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1361
                     netlink_sendmsg+0x8db/0xcb0 net/netlink/af_netlink.c:1905
                     sock_sendmsg_nosec net/socket.c:730 [inline]
                     __sock_sendmsg+0x221/0x270 net/socket.c:745
                     __sys_sendto+0x3a4/0x4f0 net/socket.c:2192
                     __do_sys_sendto net/socket.c:2204 [inline]
                     __se_sys_sendto net/socket.c:2200 [inline]
                     __x64_sys_sendto+0xde/0x100 net/socket.c:2200
                     do_syscall_x64 arch/x86/entry/common.c:52 [inline]
                     do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
                    entry_SYSCALL_64_after_hwframe+0x77/0x7f
   IN-SOFTIRQ-W at:
                     lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
                     __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
                     _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
                     spin_lock include/linux/spinlock.h:351 [inline]
                     br_forward_delay_timer_expired+0x50/0x440 net/bridge/br_stp_timer.c:86
                     call_timer_fn+0x18e/0x650 kernel/time/timer.c:1792
                     expire_timers kernel/time/timer.c:1843 [inline]
                     __run_timers kernel/time/timer.c:2417 [inline]
                     __run_timer_base+0x66a/0x8e0 kernel/time/timer.c:2428
                     run_timer_base kernel/time/timer.c:2437 [inline]
                     run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2447
                     handle_softirqs+0x2c4/0x970 kernel/softirq.c:554
                     __do_softirq kernel/softirq.c:588 [inline]
                     invoke_softirq kernel/softirq.c:428 [inline]
                     __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637
                     irq_exit_rcu+0x9/0x30 kernel/softirq.c:649
                     instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
                     sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043
                     asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
                     lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5758
                     fs_reclaim_acquire+0xaf/0x140 mm/page_alloc.c:3800
                     might_alloc include/linux/sched/mm.h:334 [inline]
                     slab_pre_alloc_hook mm/slub.c:3890 [inline]
                     slab_alloc_node mm/slub.c:3980 [inline]
                     kmalloc_trace_noprof+0x3d/0x2c0 mm/slub.c:4147
                     kmalloc_noprof include/linux/slab.h:660 [inline]
                     kzalloc_noprof include/linux/slab.h:778 [inline]
                     class_dir_create_and_add drivers/base/core.c:3255 [inline]
                     get_device_parent+0x2a7/0x410 drivers/base/core.c:3315
                     device_add+0x325/0xbf0 drivers/base/core.c:3645
                     netdev_register_kobject+0x17e/0x320 net/core/net-sysfs.c:2136
                     register_netdevice+0x11d5/0x19e0 net/core/dev.c:10375
                     nsim_init_netdevsim drivers/net/netdevsim/netdev.c:690 [inline]
                     nsim_create+0x647/0x890 drivers/net/netdevsim/netdev.c:750
                     __nsim_dev_port_add+0x6c0/0xae0 drivers/net/netdevsim/dev.c:1390
                     nsim_dev_port_add_all drivers/net/netdevsim/dev.c:1446 [inline]
                     nsim_dev_reload_create drivers/net/netdevsim/dev.c:1498 [inline]
                     nsim_dev_reload_up+0x69b/0x8e0 drivers/net/netdevsim/dev.c:985
                     devlink_reload+0x478/0x870 net/devlink/dev.c:474
                     devlink_nl_reload_doit+0xbd6/0xe50 net/devlink/dev.c:586
                     genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline]
                     genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
                     genl_rcv_msg+0xb14/0xec0 net/netlink/genetlink.c:1210
                     netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2564
                     genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
                     netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
                     netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1361
                     netlink_sendmsg+0x8db/0xcb0 net/netlink/af_netlink.c:1905
                     sock_sendmsg_nosec net/socket.c:730 [inline]
                     __sock_sendmsg+0x221/0x270 net/socket.c:745
                     ____sys_sendmsg+0x525/0x7d0 net/socket.c:2585
                     ___sys_sendmsg net/socket.c:2639 [inline]
                     __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2668
                     do_syscall_x64 arch/x86/entry/common.c:52 [inline]
                     do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
                    entry_SYSCALL_64_after_hwframe+0x77/0x7f
   INITIAL USE at:
                    lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
                    __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
                    _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
                    spin_lock_bh include/linux/spinlock.h:356 [inline]
                    br_add_if+0xb34/0xef0 net/bridge/br_if.c:682
                    do_set_master net/core/rtnetlink.c:2701 [inline]
                    do_setlink+0xe70/0x41f0 net/core/rtnetlink.c:2907
                    __rtnl_newlink net/core/rtnetlink.c:3696 [inline]
                    rtnl_newlink+0x180b/0x20a0 net/core/rtnetlink.c:3743
                    rtnetlink_rcv_msg+0x89b/0x1180 net/core/rtnetlink.c:6635
                    netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2564
                    netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
                    netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1361
                    netlink_sendmsg+0x8db/0xcb0 net/netlink/af_netlink.c:1905
                    sock_sendmsg_nosec net/socket.c:730 [inline]
                    __sock_sendmsg+0x221/0x270 net/socket.c:745
                    __sys_sendto+0x3a4/0x4f0 net/socket.c:2192
                    __do_sys_sendto net/socket.c:2204 [inline]
                    __se_sys_sendto net/socket.c:2200 [inline]
                    __x64_sys_sendto+0xde/0x100 net/socket.c:2200
                    do_syscall_x64 arch/x86/entry/common.c:52 [inline]
                    do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
                   entry_SYSCALL_64_after_hwframe+0x77/0x7f
 }
 ... key      at: [] br_dev_setup.__key+0x0/0x20

the dependencies between the lock to be acquired
 and SOFTIRQ-irq-unsafe lock:
-> (netdev_rename_lock.seqcount){+.+.}-{0:0} {
   HARDIRQ-ON-W at:
                     lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
                     do_write_seqcount_begin_nested include/linux/seqlock.h:469 [inline]
                     do_write_seqcount_begin include/linux/seqlock.h:495 [inline]
                     write_seqlock include/linux/seqlock.h:823 [inline]
                     dev_change_name+0x184/0x920 net/core/dev.c:1229
                     do_setlink+0xa4b/0x41f0 net/core/rtnetlink.c:2880
                     __rtnl_newlink net/core/rtnetlink.c:3696 [inline]
                     rtnl_newlink+0x180b/0x20a0 net/core/rtnetlink.c:3743
                     rtnetlink_rcv_msg+0x89b/0x1180 net/core/rtnetlink.c:6635
                     netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2564
                     netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
                     netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1361
                     netlink_sendmsg+0x8db/0xcb0 net/netlink/af_netlink.c:1905
                     sock_sendmsg_nosec net/socket.c:730 [inline]
                     __sock_sendmsg+0x221/0x270 net/socket.c:745
                     __sys_sendto+0x3a4/0x4f0 net/socket.c:2192
                     __do_sys_sendto net/socket.c:2204 [inline]
                     __se_sys_sendto net/socket.c:2200 [inline]
                     __x64_sys_sendto+0xde/0x100 net/socket.c:2200
                     do_syscall_x64 arch/x86/entry/common.c:52 [inline]
                     do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
                    entry_SYSCALL_64_after_hwframe+0x77/0x7f
   SOFTIRQ-ON-W at:
                     lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
                     do_write_seqcount_begin_nested include/linux/seqlock.h:469 [inline]
                     do_write_seqcount_begin include/linux/seqlock.h:495 [inline]
                     write_seqlock include/linux/seqlock.h:823 [inline]
                     dev_change_name+0x184/0x920 net/core/dev.c:1229
                     do_setlink+0xa4b/0x41f0 net/core/rtnetlink.c:2880
                     __rtnl_newlink net/core/rtnetlink.c:3696 [inline]
                     rtnl_newlink+0x180b/0x20a0 net/core/rtnetlink.c:3743
                     rtnetlink_rcv_msg+0x89b/0x1180 net/core/rtnetlink.c:6635
                     netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2564
                     netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
                     netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1361
                     netlink_sendmsg+0x8db/0xcb0 net/netlink/af_netlink.c:1905
                     sock_sendmsg_nosec net/socket.c:730 [inline]
                     __sock_sendmsg+0x221/0x270 net/socket.c:745
                     __sys_sendto+0x3a4/0x4f0 net/socket.c:2192
                     __do_sys_sendto net/socket.c:2204 [inline]
                     __se_sys_sendto net/socket.c:2200 [inline]
                     __x64_sys_sendto+0xde/0x100 net/socket.c:2200
                     do_syscall_x64 arch/x86/entry/common.c:52 [inline]
                     do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
                    entry_SYSCALL_64_after_hwframe+0x77/0x7f
   INITIAL USE at:
                    lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
                    do_write_seqcount_begin_nested include/linux/seqlock.h:469 [inline]
                    do_write_seqcount_begin include/linux/seqlock.h:495 [inline]
                    write_seqlock include/linux/seqlock.h:823 [inline]
                    dev_change_name+0x184/0x920 net/core/dev.c:1229
                    do_setlink+0xa4b/0x41f0 net/core/rtnetlink.c:2880
                    __rtnl_newlink net/core/rtnetlink.c:3696 [inline]
                    rtnl_newlink+0x180b/0x20a0 net/core/rtnetlink.c:3743
                    rtnetlink_rcv_msg+0x89b/0x1180 net/core/rtnetlink.c:6635
                    netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2564
                    netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
                    netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1361
                    netlink_sendmsg+0x8db/0xcb0 net/netlink/af_netlink.c:1905
                    sock_sendmsg_nosec net/socket.c:730 [inline]
                    __sock_sendmsg+0x221/0x270 net/socket.c:745
                    __sys_sendto+0x3a4/0x4f0 net/socket.c:2192
                    __do_sys_sendto net/socket.c:2204 [inline]
                    __se_sys_sendto net/socket.c:2200 [inline]
                    __x64_sys_sendto+0xde/0x100 net/socket.c:2200
                    do_syscall_x64 arch/x86/entry/common.c:52 [inline]
                    do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
                   entry_SYSCALL_64_after_hwframe+0x77/0x7f
   INITIAL READ USE at:
                         lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
                         seqcount_lockdep_reader_access include/linux/seqlock.h:72 [inline]
                         read_seqbegin include/linux/seqlock.h:772 [inline]
                         netdev_copy_name+0x168/0x2c0 net/core/dev.c:949
                         rtnl_fill_ifinfo+0x38e/0x2270 net/core/rtnetlink.c:1839
                         rtmsg_ifinfo_build_skb+0x18a/0x260 net/core/rtnetlink.c:4073
                         rtmsg_ifinfo_event net/core/rtnetlink.c:4107 [inline]
                         rtmsg_ifinfo+0x91/0x1b0 net/core/rtnetlink.c:4116
                         register_netdevice+0x1665/0x19e0 net/core/dev.c:10422
                         register_netdev+0x3b/0x50 net/core/dev.c:10512
                         loopback_net_init+0x73/0x150 drivers/net/loopback.c:217
                         ops_init+0x359/0x610 net/core/net_namespace.c:139
                         __register_pernet_operations net/core/net_namespace.c:1247 [inline]
                         register_pernet_operations+0x2cb/0x660 net/core/net_namespace.c:1320
                         register_pernet_device+0x33/0x80 net/core/net_namespace.c:1407
                         net_dev_init+0xfcd/0x10d0 net/core/dev.c:11956
                         do_one_initcall+0x248/0x880 init/main.c:1267
                         do_initcall_level+0x157/0x210 init/main.c:1329
                         do_initcalls+0x3f/0x80 init/main.c:1345
                         kernel_init_freeable+0x435/0x5d0 init/main.c:1578
                         kernel_init+0x1d/0x2b0 init/main.c:1467
                         ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
                         ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 }
 ... key      at: [] netdev_rename_lock+0x8/0xa0
 ... acquired at:
    lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
    seqcount_lockdep_reader_access include/linux/seqlock.h:72 [inline]
    read_seqbegin include/linux/seqlock.h:772 [inline]
    netdev_copy_name+0x168/0x2c0 net/core/dev.c:949
    rtnl_fill_ifinfo+0x38e/0x2270 net/core/rtnetlink.c:1839
    rtmsg_ifinfo_build_skb+0x18a/0x260 net/core/rtnetlink.c:4073
    rtmsg_ifinfo_event net/core/rtnetlink.c:4107 [inline]
    rtmsg_ifinfo+0x91/0x1b0 net/core/rtnetlink.c:4116
    __dev_notify_flags+0xf7/0x400 net/core/dev.c:8816
    __dev_set_promiscuity+0x152/0x5a0 net/core/dev.c:8588
    dev_set_promiscuity+0x51/0xe0 net/core/dev.c:8608
    team_change_rx_flags+0x203/0x330 drivers/net/team/team_core.c:1771
    dev_change_rx_flags net/core/dev.c:8541 [inline]
    __dev_set_promiscuity+0x406/0x5a0 net/core/dev.c:8585
    dev_set_promiscuity+0x51/0xe0 net/core/dev.c:8608
    br_port_clear_promisc net/bridge/br_if.c:135 [inline]
    br_manage_promisc+0x505/0x590 net/bridge/br_if.c:172
    nbp_update_port_count net/bridge/br_if.c:242 [inline]
    br_port_flags_change+0x161/0x1f0 net/bridge/br_if.c:761
    br_setport+0xcb5/0x16d0 net/bridge/br_netlink.c:1000
    br_port_slave_changelink+0x135/0x150 net/bridge/br_netlink.c:1213
    __rtnl_newlink net/core/rtnetlink.c:3689 [inline]
    rtnl_newlink+0x169f/0x20a0 net/core/rtnetlink.c:3743
    rtnetlink_rcv_msg+0x89b/0x1180 net/core/rtnetlink.c:6635
    netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2564
    netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
    netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1361
    netlink_sendmsg+0x8db/0xcb0 net/netlink/af_netlink.c:1905
    sock_sendmsg_nosec net/socket.c:730 [inline]
    __sock_sendmsg+0x221/0x270 net/socket.c:745
    ____sys_sendmsg+0x525/0x7d0 net/socket.c:2585
    ___sys_sendmsg net/socket.c:2639 [inline]
    __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2668
    do_syscall_x64 arch/x86/entry/common.c:52 [inline]
    do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
   entry_SYSCALL_64_after_hwframe+0x77/0x7f

stack backtrace:
CPU: 0 PID: 9449 Comm: syz-executor.2 Not tainted 6.10.0-rc2-syzkaller-00249-gbe27b8965297 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Call Trace:
 
  __dump_stack lib/dump_stack.c:88 [inline]
  dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
  print_bad_irq_dependency kernel/locking/lockdep.c:2626 [inline]
  check_irq_usage kernel/locking/lockdep.c:2865 [inline]
  check_prev_add kernel/locking/lockdep.c:3138 [inline]
  check_prevs_add kernel/locking/lockdep.c:3253 [inline]
  validate_chain+0x4de0/0x5900 kernel/locking/lockdep.c:3869
  __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
  lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
  seqcount_lockdep_reader_access include/linux/seqlock.h:72 [inline]
  read_seqbegin include/linux/seqlock.h:772 [inline]
  netdev_copy_name+0x168/0x2c0 net/core/dev.c:949
  rtnl_fill_ifinfo+0x38e/0x2270 net/core/rtnetlink.c:1839
  rtmsg_ifinfo_build_skb+0x18a/0x260 net/core/rtnetlink.c:4073
  rtmsg_ifinfo_event net/core/rtnetlink.c:4107 [inline]
  rtmsg_ifinfo+0x91/0x1b0 net/core/rtnetlink.c:4116
  __dev_notify_flags+0xf7/0x400 net/core/dev.c:8816
  __dev_set_promiscuity+0x152/0x5a0 net/core/dev.c:8588
  dev_set_promiscuity+0x51/0xe0 net/core/dev.c:8608
  team_change_rx_flags+0x203/0x330 drivers/net/team/team_core.c:1771
  dev_change_rx_flags net/core/dev.c:8541 [inline]
  __dev_set_promiscuity+0x406/0x5a0 net/core/dev.c:8585
  dev_set_promiscuity+0x51/0xe0 net/core/dev.c:8608
  br_port_clear_promisc net/bridge/br_if.c:135 [inline]
  br_manage_promisc+0x505/0x590 net/bridge/br_if.c:172
  nbp_update_port_count net/bridge/br_if.c:242 [inline]
  br_port_flags_change+0x161/0x1f0 net/bridge/br_if.c:761
  br_setport+0xcb5/0x16d0 net/bridge/br_netlink.c:1000
  br_port_slave_changelink+0x135/0x150 net/bridge/br_netlink.c:1213
  __rtnl_newlink net/core/rtnetlink.c:3689 [inline]
  rtnl_newlink+0x169f/0x20a0 net/core/rtnetlink.c:3743
  rtnetlink_rcv_msg+0x89b/0x1180 net/core/rtnetlink.c:6635
  netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2564
  netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
  netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1361
  netlink_sendmsg+0x8db/0xcb0 net/netlink/af_netlink.c:1905
  sock_sendmsg_nosec net/socket.c:730 [inline]
  __sock_sendmsg+0x221/0x270 net/socket.c:745
  ____sys_sendmsg+0x525/0x7d0 net/socket.c:2585
  ___sys_sendmsg net/socket.c:2639 [inline]
  __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2668
  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
  do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3b3047cf29
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3b311740c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f3b305b4050 RCX: 00007f3b3047cf29
RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000008
RBP: 00007f3b304ec074 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f3b305b4050 R15: 00007ffca2f3dc68
 

Fixes: 0840556e5a3a ("net: Protect dev->name by seqlock.")
Reported-by: syzbot 
Signed-off-by: Eric Dumazet 
Cc: Kuniyuki Iwashima 
Reviewed-by: Kuniyuki Iwashima 
Signed-off-by: David S. Miller

net: do not leave a dangling sk pointer, when socket creation fails

2024-06-20T08:43:14+00:00

It is possible to trigger a use-after-free by:
  * attaching an fentry probe to __sock_release() and the probe calling the
    bpf_get_socket_cookie() helper
  * running traceroute -I 1.1.1.1 on a freshly booted VM

A KASAN enabled kernel will log something like below (decoded and stripped):
==================================================================
BUG: KASAN: slab-use-after-free in __sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29)
Read of size 8 at addr ffff888007110dd8 by task traceroute/299

CPU: 2 PID: 299 Comm: traceroute Tainted: G            E      6.10.0-rc2+ #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 
dump_stack_lvl (lib/dump_stack.c:117 (discriminator 1))
print_report (mm/kasan/report.c:378 mm/kasan/report.c:488)
? __sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29)
kasan_report (mm/kasan/report.c:603)
? __sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29)
kasan_check_range (mm/kasan/generic.c:183 mm/kasan/generic.c:189)
__sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29)
bpf_get_socket_ptr_cookie (./arch/x86/include/asm/preempt.h:94 ./include/linux/sock_diag.h:42 net/core/filter.c:5094 net/core/filter.c:5092)
bpf_prog_875642cf11f1d139___sock_release+0x6e/0x8e
bpf_trampoline_6442506592+0x47/0xaf
__sock_release (net/socket.c:652)
__sock_create (net/socket.c:1601)
...
Allocated by task 299 on cpu 2 at 78.328492s:
kasan_save_stack (mm/kasan/common.c:48)
kasan_save_track (mm/kasan/common.c:68)
__kasan_slab_alloc (mm/kasan/common.c:312 mm/kasan/common.c:338)
kmem_cache_alloc_noprof (mm/slub.c:3941 mm/slub.c:4000 mm/slub.c:4007)
sk_prot_alloc (net/core/sock.c:2075)
sk_alloc (net/core/sock.c:2134)
inet_create (net/ipv4/af_inet.c:327 net/ipv4/af_inet.c:252)
__sock_create (net/socket.c:1572)
__sys_socket (net/socket.c:1660 net/socket.c:1644 net/socket.c:1706)
__x64_sys_socket (net/socket.c:1718)
do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)

Freed by task 299 on cpu 2 at 78.328502s:
kasan_save_stack (mm/kasan/common.c:48)
kasan_save_track (mm/kasan/common.c:68)
kasan_save_free_info (mm/kasan/generic.c:582)
poison_slab_object (mm/kasan/common.c:242)
__kasan_slab_free (mm/kasan/common.c:256)
kmem_cache_free (mm/slub.c:4437 mm/slub.c:4511)
__sk_destruct (net/core/sock.c:2117 net/core/sock.c:2208)
inet_create (net/ipv4/af_inet.c:397 net/ipv4/af_inet.c:252)
__sock_create (net/socket.c:1572)
__sys_socket (net/socket.c:1660 net/socket.c:1644 net/socket.c:1706)
__x64_sys_socket (net/socket.c:1718)
do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)

Fix this by clearing the struct socket reference in sk_common_release() to cover
all protocol families create functions, which may already attached the
reference to the sk object with sock_init_data().

Fixes: c5dbb89fc2ac ("bpf: Expose bpf_get_socket_cookie to tracing programs")
Suggested-by: Kuniyuki Iwashima 
Signed-off-by: Ignat Korchagin 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/netdev/20240613194047.36478-1-kuniyu@amazon.com/T/
Reviewed-by: Kuniyuki Iwashima 
Reviewed-by: D. Wythe 
Link: https://lore.kernel.org/r/20240617210205.67311-1-ignat@cloudflare.com
Signed-off-by: Paolo Abeni

netns: Make get_net_ns() handle zero refcount net

2024-06-18T08:59:52+00:00

Syzkaller hit a warning:
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 3 PID: 7890 at lib/refcount.c:25 refcount_warn_saturate+0xdf/0x1d0
Modules linked in:
CPU: 3 PID: 7890 Comm: tun Not tainted 6.10.0-rc3-00100-gcaa4f9578aba-dirty #310
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
RIP: 0010:refcount_warn_saturate+0xdf/0x1d0
Code: 41 49 04 31 ff 89 de e8 9f 1e cd fe 84 db 75 9c e8 76 26 cd fe c6 05 b6 41 49 04 01 90 48 c7 c7 b8 8e 25 86 e8 d2 05 b5 fe 90 <0f> 0b 90 90 e9 79 ff ff ff e8 53 26 cd fe 0f b6 1
RSP: 0018:ffff8881067b7da0 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff811c72ac
RDX: ffff8881026a2140 RSI: ffffffff811c72b5 RDI: 0000000000000001
RBP: ffff8881067b7db0 R08: 0000000000000000 R09: 205b5d3730353139
R10: 0000000000000000 R11: 205d303938375420 R12: ffff8881086500c4
R13: ffff8881086500c4 R14: ffff8881086500b0 R15: ffff888108650040
FS:  00007f5b2961a4c0(0000) GS:ffff88823bd00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d7ed36fd18 CR3: 00000001482f6000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 
 ? show_regs+0xa3/0xc0
 ? __warn+0xa5/0x1c0
 ? refcount_warn_saturate+0xdf/0x1d0
 ? report_bug+0x1fc/0x2d0
 ? refcount_warn_saturate+0xdf/0x1d0
 ? handle_bug+0xa1/0x110
 ? exc_invalid_op+0x3c/0xb0
 ? asm_exc_invalid_op+0x1f/0x30
 ? __warn_printk+0xcc/0x140
 ? __warn_printk+0xd5/0x140
 ? refcount_warn_saturate+0xdf/0x1d0
 get_net_ns+0xa4/0xc0
 ? __pfx_get_net_ns+0x10/0x10
 open_related_ns+0x5a/0x130
 __tun_chr_ioctl+0x1616/0x2370
 ? __sanitizer_cov_trace_switch+0x58/0xa0
 ? __sanitizer_cov_trace_const_cmp2+0x1c/0x30
 ? __pfx_tun_chr_ioctl+0x10/0x10
 tun_chr_ioctl+0x2f/0x40
 __x64_sys_ioctl+0x11b/0x160
 x64_sys_call+0x1211/0x20d0
 do_syscall_64+0x9e/0x1d0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5b28f165d7
Code: b3 66 90 48 8b 05 b1 48 2d 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 81 48 2d 00 8
RSP: 002b:00007ffc2b59c5e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5b28f165d7
RDX: 0000000000000000 RSI: 00000000000054e3 RDI: 0000000000000003
RBP: 00007ffc2b59c650 R08: 00007f5b291ed8c0 R09: 00007f5b2961a4c0
R10: 0000000029690010 R11: 0000000000000246 R12: 0000000000400730
R13: 00007ffc2b59cf40 R14: 0000000000000000 R15: 0000000000000000
 
Kernel panic - not syncing: kernel: panic_on_warn set ...

This is trigger as below:
          ns0                                    ns1
tun_set_iff() //dev is tun0
   tun->dev = dev
//ip link set tun0 netns ns1
                                       put_net() //ref is 0
__tun_chr_ioctl() //TUNGETDEVNETNS
   net = dev_net(tun->dev);
   open_related_ns(&net->ns, get_net_ns); //ns1
     get_net_ns()
        get_net() //addition on 0

Use maybe_get_net() in get_net_ns in case net's ref is zero to fix this

Fixes: 0c3e0e3bb623 ("tun: Add ioctl() TUNGETDEVNETNS cmd to allow obtaining real net ns of tun device")
Signed-off-by: Yue Haibing 
Link: https://lore.kernel.org/r/20240614131302.2698509-1-yuehaibing@huawei.com
Signed-off-by: Paolo Abeni

netdev-genl: fix error codes when outputting XDP features

2024-06-15T01:04:29+00:00

-EINVAL will interrupt the dump. The correct error to return
if we have more data to dump is -EMSGSIZE.

Discovered by doing:

  for i in `seq 80`; do ip link add type veth; done
  ./cli.py --dbg-small-recv 5300 --spec netdev.yaml --dump dev-get >> /dev/null
  [...]
     nl_len = 64 (48) nl_flags = 0x0 nl_type = 19
     nl_len = 20 (4) nl_flags = 0x2 nl_type = 3
  	error: -22

Fixes: d3d854fd6a1d ("netdev-genl: create a simple family for netdev stuff")
Reviewed-by: Amritha Nambiar 
Reviewed-by: Eric Dumazet 
Link: https://lore.kernel.org/r/20240613213044.3675745-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski

bpf: Avoid splat in pskb_pull_reason

2024-06-14T15:20:21+00:00

syzkaller builds (CONFIG_DEBUG_NET=y) frequently trigger a debug
hint in pskb_may_pull.

We'd like to retain this debug check because it might hint at integer
overflows and other issues (kernel code should pull headers, not huge
value).

In bpf case, this splat isn't interesting at all: such (nonsensical)
bpf programs are typically generated by a fuzzer anyway.

Do what Eric suggested and suppress such warning.

For CONFIG_DEBUG_NET=n we don't need the extra check because
pskb_may_pull will do the right thing: return an error without the
WARN() backtrace.

Fixes: 219eee9c0d16 ("net: skbuff: add overflow debug check to pull/push helpers")
Reported-by: syzbot+0c4150bff9fff3bf023c@syzkaller.appspotmail.com
Suggested-by: Eric Dumazet 
Signed-off-by: Florian Westphal 
Signed-off-by: Daniel Borkmann 
Reviewed-by: Eric Dumazet 
Acked-by: Daniel Borkmann 
Closes: https://syzkaller.appspot.com/bug?extid=0c4150bff9fff3bf023c
Link: https://lore.kernel.org/netdev/9f254c96-54f2-4457-b7ab-1d9f6187939c@gmail.com/
Link: https://lore.kernel.org/bpf/20240614101801.9496-1-fw@strlen.de