diff mbox series

[net] ipv6: prevent possible NULL dereference in rt6_probe()

Message ID 20240615151454.166404-1-edumazet@google.com (mailing list archive)
State Accepted
Commit b86762dbe19a62e785c189f313cda5b989931f37
Delegated to: Netdev Maintainers
Headers show
Series [net] ipv6: prevent possible NULL dereference in rt6_probe() | expand

Checks

Context Check Description
netdev/series_format success Single patches do not need cover letters
netdev/tree_selection success Clearly marked for net
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 860 this patch: 860
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 5 of 6 maintainers
netdev/build_clang success Errors and warnings before: 863 this patch: 863
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 864 this patch: 864
netdev/checkpatch warning WARNING: Possible repeated word: 'Google'
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-06-16--18-00 (tests: 659)

Commit Message

Eric Dumazet June 15, 2024, 3:14 p.m. UTC 
syzbot caught a NULL dereference in rt6_probe() [1]

Bail out if  __in6_dev_get() returns NULL.

[1]
Oops: general protection fault, probably for non-canonical address 0xdffffc00000000cb: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000658-0x000000000000065f]
CPU: 1 PID: 22444 Comm: syz-executor.0 Not tainted 6.10.0-rc2-syzkaller-00383-gb8481381d4e2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
 RIP: 0010:rt6_probe net/ipv6/route.c:656 [inline]
 RIP: 0010:find_match+0x8c4/0xf50 net/ipv6/route.c:758
Code: 14 fd f7 48 8b 85 38 ff ff ff 48 c7 45 b0 00 00 00 00 48 8d b8 5c 06 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 19
RSP: 0018:ffffc900034af070 EFLAGS: 00010203
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc90004521000
RDX: 00000000000000cb RSI: ffffffff8990d0cd RDI: 000000000000065c
RBP: ffffc900034af150 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000002 R12: 000000000000000a
R13: 1ffff92000695e18 R14: ffff8880244a1d20 R15: 0000000000000000
FS:  00007f4844a5a6c0(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31b27000 CR3: 000000002d42c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
  rt6_nh_find_match+0xfa/0x1a0 net/ipv6/route.c:784
  nexthop_for_each_fib6_nh+0x26d/0x4a0 net/ipv4/nexthop.c:1496
  __find_rr_leaf+0x6e7/0xe00 net/ipv6/route.c:825
  find_rr_leaf net/ipv6/route.c:853 [inline]
  rt6_select net/ipv6/route.c:897 [inline]
  fib6_table_lookup+0x57e/0xa30 net/ipv6/route.c:2195
  ip6_pol_route+0x1cd/0x1150 net/ipv6/route.c:2231
  pol_lookup_func include/net/ip6_fib.h:616 [inline]
  fib6_rule_lookup+0x386/0x720 net/ipv6/fib6_rules.c:121
  ip6_route_output_flags_noref net/ipv6/route.c:2639 [inline]
  ip6_route_output_flags+0x1d0/0x640 net/ipv6/route.c:2651
  ip6_dst_lookup_tail.constprop.0+0x961/0x1760 net/ipv6/ip6_output.c:1147
  ip6_dst_lookup_flow+0x99/0x1d0 net/ipv6/ip6_output.c:1250
  rawv6_sendmsg+0xdab/0x4340 net/ipv6/raw.c:898
  inet_sendmsg+0x119/0x140 net/ipv4/af_inet.c:853
  sock_sendmsg_nosec net/socket.c:730 [inline]
  __sock_sendmsg net/socket.c:745 [inline]
  sock_write_iter+0x4b8/0x5c0 net/socket.c:1160
  new_sync_write fs/read_write.c:497 [inline]
  vfs_write+0x6b6/0x1140 fs/read_write.c:590
  ksys_write+0x1f8/0x260 fs/read_write.c:643
  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
  do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Fixes: 52e1635631b3 ("[IPV6]: ROUTE: Add router_probe_interval sysctl.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 net/ipv6/route.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Jason Xing June 16, 2024, 12:59 a.m. UTC | #1 
On Sat, Jun 15, 2024 at 11:15 PM Eric Dumazet <edumazet@google.com> wrote:
>
> syzbot caught a NULL dereference in rt6_probe() [1]
>
> Bail out if  __in6_dev_get() returns NULL.
>
> [1]
> Oops: general protection fault, probably for non-canonical address 0xdffffc00000000cb: 0000 [#1] PREEMPT SMP KASAN PTI
> KASAN: null-ptr-deref in range [0x0000000000000658-0x000000000000065f]
> CPU: 1 PID: 22444 Comm: syz-executor.0 Not tainted 6.10.0-rc2-syzkaller-00383-gb8481381d4e2 #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
>  RIP: 0010:rt6_probe net/ipv6/route.c:656 [inline]
>  RIP: 0010:find_match+0x8c4/0xf50 net/ipv6/route.c:758
> Code: 14 fd f7 48 8b 85 38 ff ff ff 48 c7 45 b0 00 00 00 00 48 8d b8 5c 06 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 19
> RSP: 0018:ffffc900034af070 EFLAGS: 00010203
> RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc90004521000
> RDX: 00000000000000cb RSI: ffffffff8990d0cd RDI: 000000000000065c
> RBP: ffffc900034af150 R08: 0000000000000005 R09: 0000000000000000
> R10: 0000000000000001 R11: 0000000000000002 R12: 000000000000000a
> R13: 1ffff92000695e18 R14: ffff8880244a1d20 R15: 0000000000000000
> FS:  00007f4844a5a6c0(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000001b31b27000 CR3: 000000002d42c000 CR4: 00000000003506f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>  <TASK>
>   rt6_nh_find_match+0xfa/0x1a0 net/ipv6/route.c:784
>   nexthop_for_each_fib6_nh+0x26d/0x4a0 net/ipv4/nexthop.c:1496
>   __find_rr_leaf+0x6e7/0xe00 net/ipv6/route.c:825
>   find_rr_leaf net/ipv6/route.c:853 [inline]
>   rt6_select net/ipv6/route.c:897 [inline]
>   fib6_table_lookup+0x57e/0xa30 net/ipv6/route.c:2195
>   ip6_pol_route+0x1cd/0x1150 net/ipv6/route.c:2231
>   pol_lookup_func include/net/ip6_fib.h:616 [inline]
>   fib6_rule_lookup+0x386/0x720 net/ipv6/fib6_rules.c:121
>   ip6_route_output_flags_noref net/ipv6/route.c:2639 [inline]
>   ip6_route_output_flags+0x1d0/0x640 net/ipv6/route.c:2651
>   ip6_dst_lookup_tail.constprop.0+0x961/0x1760 net/ipv6/ip6_output.c:1147
>   ip6_dst_lookup_flow+0x99/0x1d0 net/ipv6/ip6_output.c:1250
>   rawv6_sendmsg+0xdab/0x4340 net/ipv6/raw.c:898
>   inet_sendmsg+0x119/0x140 net/ipv4/af_inet.c:853
>   sock_sendmsg_nosec net/socket.c:730 [inline]
>   __sock_sendmsg net/socket.c:745 [inline]
>   sock_write_iter+0x4b8/0x5c0 net/socket.c:1160
>   new_sync_write fs/read_write.c:497 [inline]
>   vfs_write+0x6b6/0x1140 fs/read_write.c:590
>   ksys_write+0x1f8/0x260 fs/read_write.c:643
>   do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>   do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> Fixes: 52e1635631b3 ("[IPV6]: ROUTE: Add router_probe_interval sysctl.")
> Signed-off-by: Eric Dumazet <edumazet@google.com>

Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
David Ahern June 16, 2024, 6:19 p.m. UTC | #2 
On 6/15/24 9:14 AM, Eric Dumazet wrote:
> syzbot caught a NULL dereference in rt6_probe() [1]
> 
> Bail out if  __in6_dev_get() returns NULL.
> 
...

> Fixes: 52e1635631b3 ("[IPV6]: ROUTE: Add router_probe_interval sysctl.")
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> ---
>  net/ipv6/route.c | 2 ++
>  1 file changed, 2 insertions(+)
> 



Reviewed-by: David Ahern <dsahern@kernel.org>
patchwork-bot+netdevbpf@kernel.org June 18, 2024, 1:10 a.m. UTC | #3 
Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Sat, 15 Jun 2024 15:14:54 +0000 you wrote:
> syzbot caught a NULL dereference in rt6_probe() [1]
> 
> Bail out if  __in6_dev_get() returns NULL.
> 
> [1]
> Oops: general protection fault, probably for non-canonical address 0xdffffc00000000cb: 0000 [#1] PREEMPT SMP KASAN PTI
> KASAN: null-ptr-deref in range [0x0000000000000658-0x000000000000065f]
> CPU: 1 PID: 22444 Comm: syz-executor.0 Not tainted 6.10.0-rc2-syzkaller-00383-gb8481381d4e2 #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
>  RIP: 0010:rt6_probe net/ipv6/route.c:656 [inline]
>  RIP: 0010:find_match+0x8c4/0xf50 net/ipv6/route.c:758
> Code: 14 fd f7 48 8b 85 38 ff ff ff 48 c7 45 b0 00 00 00 00 48 8d b8 5c 06 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 19
> RSP: 0018:ffffc900034af070 EFLAGS: 00010203
> RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc90004521000
> RDX: 00000000000000cb RSI: ffffffff8990d0cd RDI: 000000000000065c
> RBP: ffffc900034af150 R08: 0000000000000005 R09: 0000000000000000
> R10: 0000000000000001 R11: 0000000000000002 R12: 000000000000000a
> R13: 1ffff92000695e18 R14: ffff8880244a1d20 R15: 0000000000000000
> FS:  00007f4844a5a6c0(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000001b31b27000 CR3: 000000002d42c000 CR4: 00000000003506f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>  <TASK>
>   rt6_nh_find_match+0xfa/0x1a0 net/ipv6/route.c:784
>   nexthop_for_each_fib6_nh+0x26d/0x4a0 net/ipv4/nexthop.c:1496
>   __find_rr_leaf+0x6e7/0xe00 net/ipv6/route.c:825
>   find_rr_leaf net/ipv6/route.c:853 [inline]
>   rt6_select net/ipv6/route.c:897 [inline]
>   fib6_table_lookup+0x57e/0xa30 net/ipv6/route.c:2195
>   ip6_pol_route+0x1cd/0x1150 net/ipv6/route.c:2231
>   pol_lookup_func include/net/ip6_fib.h:616 [inline]
>   fib6_rule_lookup+0x386/0x720 net/ipv6/fib6_rules.c:121
>   ip6_route_output_flags_noref net/ipv6/route.c:2639 [inline]
>   ip6_route_output_flags+0x1d0/0x640 net/ipv6/route.c:2651
>   ip6_dst_lookup_tail.constprop.0+0x961/0x1760 net/ipv6/ip6_output.c:1147
>   ip6_dst_lookup_flow+0x99/0x1d0 net/ipv6/ip6_output.c:1250
>   rawv6_sendmsg+0xdab/0x4340 net/ipv6/raw.c:898
>   inet_sendmsg+0x119/0x140 net/ipv4/af_inet.c:853
>   sock_sendmsg_nosec net/socket.c:730 [inline]
>   __sock_sendmsg net/socket.c:745 [inline]
>   sock_write_iter+0x4b8/0x5c0 net/socket.c:1160
>   new_sync_write fs/read_write.c:497 [inline]
>   vfs_write+0x6b6/0x1140 fs/read_write.c:590
>   ksys_write+0x1f8/0x260 fs/read_write.c:643
>   do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>   do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
> 
> [...]

Here is the summary with links:
  - [net] ipv6: prevent possible NULL dereference in rt6_probe()
    https://git.kernel.org/netdev/net/c/b86762dbe19a

You are awesome, thank you!
diff mbox series

Patch

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 952c2bf1170942d411392b5bd5994cb057d3a983..3dc66cfb3d0726366679b67b0ac22663209fa9b7 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -638,6 +638,8 @@  static void rt6_probe(struct fib6_nh *fib6_nh)
 	rcu_read_lock();
 	last_probe = READ_ONCE(fib6_nh->last_probe);
 	idev = __in6_dev_get(dev);
+	if (!idev)
+		goto out;
 	neigh = __ipv6_neigh_lookup_noref(dev, nh_gw);
 	if (neigh) {
 		if (READ_ONCE(neigh->nud_state) & NUD_VALID)