diff mbox series

[net] ipv6: prevent possible NULL deref in fib6_nh_init()

Message ID 20240614082002.26407-1-edumazet@google.com (mailing list archive)
State Accepted
Commit 2eab4543a2204092c3a7af81d7d6c506e59a03a6
Delegated to: Netdev Maintainers
Headers show
Series [net] ipv6: prevent possible NULL deref in fib6_nh_init() | 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 fail 1 blamed authors not CCed: lorenzo.bianconi@redhat.com; 1 maintainers not CCed: lorenzo.bianconi@redhat.com
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 14, 2024, 8:20 a.m. UTC 
syzbot reminds us that in6_dev_get() can return NULL.

fib6_nh_init()
    ip6_validate_gw(  &idev  )
        ip6_route_check_nh(  idev  )
            *idev = in6_dev_get(dev); // can be NULL

Oops: general protection fault, probably for non-canonical address 0xdffffc00000000bc: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x00000000000005e0-0x00000000000005e7]
CPU: 0 PID: 11237 Comm: syz-executor.3 Not tainted 6.10.0-rc2-syzkaller-00249-gbe27b8965297 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
 RIP: 0010:fib6_nh_init+0x640/0x2160 net/ipv6/route.c:3606
Code: 00 00 fc ff df 4c 8b 64 24 58 48 8b 44 24 28 4c 8b 74 24 30 48 89 c1 48 89 44 24 28 48 8d 98 e0 05 00 00 48 89 d8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 0f 85 b3 17 00 00 8b 1b 31 ff 89 de e8 b8 8b
RSP: 0018:ffffc900032775a0 EFLAGS: 00010202
RAX: 00000000000000bc RBX: 00000000000005e0 RCX: 0000000000000000
RDX: 0000000000000010 RSI: ffffc90003277a54 RDI: ffff88802b3a08d8
RBP: ffffc900032778b0 R08: 00000000000002fc R09: 0000000000000000
R10: 00000000000002fc R11: 0000000000000000 R12: ffff88802b3a08b8
R13: 1ffff9200064eec8 R14: ffffc90003277a00 R15: dffffc0000000000
FS:  00007f940feb06c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000245e8000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
  ip6_route_info_create+0x99e/0x12b0 net/ipv6/route.c:3809
  ip6_route_add+0x28/0x160 net/ipv6/route.c:3853
  ipv6_route_ioctl+0x588/0x870 net/ipv6/route.c:4483
  inet6_ioctl+0x21a/0x280 net/ipv6/af_inet6.c:579
  sock_do_ioctl+0x158/0x460 net/socket.c:1222
  sock_ioctl+0x629/0x8e0 net/socket.c:1341
  vfs_ioctl fs/ioctl.c:51 [inline]
  __do_sys_ioctl fs/ioctl.c:907 [inline]
  __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
  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: 0033:0x7f940f07cea9

Fixes: 428604fb118f ("ipv6: do not set routes if disable_ipv6 has been enabled")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Lorenzo Bianconi <lorenzo@kernel.org>
---
 net/ipv6/route.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Lorenzo Bianconi June 14, 2024, 8:29 a.m. UTC | #1 
> syzbot reminds us that in6_dev_get() can return NULL.
> 
> fib6_nh_init()
>     ip6_validate_gw(  &idev  )
>         ip6_route_check_nh(  idev  )
>             *idev = in6_dev_get(dev); // can be NULL
> 
> Oops: general protection fault, probably for non-canonical address 0xdffffc00000000bc: 0000 [#1] PREEMPT SMP KASAN PTI
> KASAN: null-ptr-deref in range [0x00000000000005e0-0x00000000000005e7]
> CPU: 0 PID: 11237 Comm: syz-executor.3 Not tainted 6.10.0-rc2-syzkaller-00249-gbe27b8965297 #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
>  RIP: 0010:fib6_nh_init+0x640/0x2160 net/ipv6/route.c:3606
> Code: 00 00 fc ff df 4c 8b 64 24 58 48 8b 44 24 28 4c 8b 74 24 30 48 89 c1 48 89 44 24 28 48 8d 98 e0 05 00 00 48 89 d8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 0f 85 b3 17 00 00 8b 1b 31 ff 89 de e8 b8 8b
> RSP: 0018:ffffc900032775a0 EFLAGS: 00010202
> RAX: 00000000000000bc RBX: 00000000000005e0 RCX: 0000000000000000
> RDX: 0000000000000010 RSI: ffffc90003277a54 RDI: ffff88802b3a08d8
> RBP: ffffc900032778b0 R08: 00000000000002fc R09: 0000000000000000
> R10: 00000000000002fc R11: 0000000000000000 R12: ffff88802b3a08b8
> R13: 1ffff9200064eec8 R14: ffffc90003277a00 R15: dffffc0000000000
> FS:  00007f940feb06c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000000000000 CR3: 00000000245e8000 CR4: 00000000003506f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>  <TASK>
>   ip6_route_info_create+0x99e/0x12b0 net/ipv6/route.c:3809
>   ip6_route_add+0x28/0x160 net/ipv6/route.c:3853
>   ipv6_route_ioctl+0x588/0x870 net/ipv6/route.c:4483
>   inet6_ioctl+0x21a/0x280 net/ipv6/af_inet6.c:579
>   sock_do_ioctl+0x158/0x460 net/socket.c:1222
>   sock_ioctl+0x629/0x8e0 net/socket.c:1341
>   vfs_ioctl fs/ioctl.c:51 [inline]
>   __do_sys_ioctl fs/ioctl.c:907 [inline]
>   __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
>   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: 0033:0x7f940f07cea9
> 
> Fixes: 428604fb118f ("ipv6: do not set routes if disable_ipv6 has been enabled")
> Reported-by: syzbot <syzkaller@googlegroups.com>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Cc: Lorenzo Bianconi <lorenzo@kernel.org>
> ---
>  net/ipv6/route.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/net/ipv6/route.c b/net/ipv6/route.c
> index 952c2bf1170942d411392b5bd5994cb057d3a983..28788ffde5854f7f3fa42f76b94ef76b87d2379b 100644
> --- a/net/ipv6/route.c
> +++ b/net/ipv6/route.c
> @@ -3603,7 +3603,7 @@ int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
>  	if (!dev)
>  		goto out;
>  
> -	if (idev->cnf.disable_ipv6) {
> +	if (!idev || idev->cnf.disable_ipv6) {
>  		NL_SET_ERR_MSG(extack, "IPv6 is disabled on nexthop device");
>  		err = -EACCES;
>  		goto out;
> -- 
> 2.45.2.627.g7a2c4fd464-goog
> 

Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
David Ahern June 14, 2024, 2:40 p.m. UTC | #2 
On 6/14/24 2:20 AM, Eric Dumazet wrote:
> syzbot reminds us that in6_dev_get() can return NULL.
> 
> fib6_nh_init()
>     ip6_validate_gw(  &idev  )
>         ip6_route_check_nh(  idev  )
>             *idev = in6_dev_get(dev); // can be NULL
> 

...

> Fixes: 428604fb118f ("ipv6: do not set routes if disable_ipv6 has been enabled")
> Reported-by: syzbot <syzkaller@googlegroups.com>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Cc: Lorenzo Bianconi <lorenzo@kernel.org>
> ---
>  net/ipv6/route.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 

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 Fri, 14 Jun 2024 08:20:02 +0000 you wrote:
> syzbot reminds us that in6_dev_get() can return NULL.
> 
> fib6_nh_init()
>     ip6_validate_gw(  &idev  )
>         ip6_route_check_nh(  idev  )
>             *idev = in6_dev_get(dev); // can be NULL
> 
> [...]

Here is the summary with links:
  - [net] ipv6: prevent possible NULL deref in fib6_nh_init()
    https://git.kernel.org/netdev/net/c/2eab4543a220

You are awesome, thank you!
diff mbox series

Patch

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 952c2bf1170942d411392b5bd5994cb057d3a983..28788ffde5854f7f3fa42f76b94ef76b87d2379b 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -3603,7 +3603,7 @@  int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
 	if (!dev)
 		goto out;
 
-	if (idev->cnf.disable_ipv6) {
+	if (!idev || idev->cnf.disable_ipv6) {
 		NL_SET_ERR_MSG(extack, "IPv6 is disabled on nexthop device");
 		err = -EACCES;
 		goto out;