diff mbox series

[net] gtp: pull network headers in gtp_dev_xmit()

Message ID 20240808132455.3413916-1-edumazet@google.com (mailing list archive)
State Accepted
Commit 3a3be7ff9224f424e485287b54be00d2c6bd9c40
Delegated to: Netdev Maintainers
Headers show
Series [net] gtp: pull network headers in gtp_dev_xmit() | expand

Checks

Context Check Description
netdev/series_format success Single patches do not need cover letters
netdev/tree_selection success Clearly marked for net, async
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: 29 this patch: 29
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 1 maintainers not CCed: osmocom-net-gprs@lists.osmocom.org
netdev/build_clang success Errors and warnings before: 29 this patch: 29
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: 29 this patch: 29
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-2024-08-09--09-00 (tests: 705)

Commit Message

Eric Dumazet Aug. 8, 2024, 1:24 p.m. UTC 
syzbot/KMSAN reported use of uninit-value in get_dev_xmit() [1]

We must make sure the IPv4 or Ipv6 header is pulled in skb->head
before accessing fields in them.

Use pskb_inet_may_pull() to fix this issue.

[1]
BUG: KMSAN: uninit-value in ipv6_pdp_find drivers/net/gtp.c:220 [inline]
 BUG: KMSAN: uninit-value in gtp_build_skb_ip6 drivers/net/gtp.c:1229 [inline]
 BUG: KMSAN: uninit-value in gtp_dev_xmit+0x1424/0x2540 drivers/net/gtp.c:1281
  ipv6_pdp_find drivers/net/gtp.c:220 [inline]
  gtp_build_skb_ip6 drivers/net/gtp.c:1229 [inline]
  gtp_dev_xmit+0x1424/0x2540 drivers/net/gtp.c:1281
  __netdev_start_xmit include/linux/netdevice.h:4913 [inline]
  netdev_start_xmit include/linux/netdevice.h:4922 [inline]
  xmit_one net/core/dev.c:3580 [inline]
  dev_hard_start_xmit+0x247/0xa20 net/core/dev.c:3596
  __dev_queue_xmit+0x358c/0x5610 net/core/dev.c:4423
  dev_queue_xmit include/linux/netdevice.h:3105 [inline]
  packet_xmit+0x9c/0x6c0 net/packet/af_packet.c:276
  packet_snd net/packet/af_packet.c:3145 [inline]
  packet_sendmsg+0x90e3/0xa3a0 net/packet/af_packet.c:3177
  sock_sendmsg_nosec net/socket.c:730 [inline]
  __sock_sendmsg+0x30f/0x380 net/socket.c:745
  __sys_sendto+0x685/0x830 net/socket.c:2204
  __do_sys_sendto net/socket.c:2216 [inline]
  __se_sys_sendto net/socket.c:2212 [inline]
  __x64_sys_sendto+0x125/0x1d0 net/socket.c:2212
  x64_sys_call+0x3799/0x3c10 arch/x86/include/generated/asm/syscalls_64.h:45
  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
  do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
  slab_post_alloc_hook mm/slub.c:3994 [inline]
  slab_alloc_node mm/slub.c:4037 [inline]
  kmem_cache_alloc_node_noprof+0x6bf/0xb80 mm/slub.c:4080
  kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:583
  __alloc_skb+0x363/0x7b0 net/core/skbuff.c:674
  alloc_skb include/linux/skbuff.h:1320 [inline]
  alloc_skb_with_frags+0xc8/0xbf0 net/core/skbuff.c:6526
  sock_alloc_send_pskb+0xa81/0xbf0 net/core/sock.c:2815
  packet_alloc_skb net/packet/af_packet.c:2994 [inline]
  packet_snd net/packet/af_packet.c:3088 [inline]
  packet_sendmsg+0x749c/0xa3a0 net/packet/af_packet.c:3177
  sock_sendmsg_nosec net/socket.c:730 [inline]
  __sock_sendmsg+0x30f/0x380 net/socket.c:745
  __sys_sendto+0x685/0x830 net/socket.c:2204
  __do_sys_sendto net/socket.c:2216 [inline]
  __se_sys_sendto net/socket.c:2212 [inline]
  __x64_sys_sendto+0x125/0x1d0 net/socket.c:2212
  x64_sys_call+0x3799/0x3c10 arch/x86/include/generated/asm/syscalls_64.h:45
  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
  do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 0 UID: 0 PID: 7115 Comm: syz.1.515 Not tainted 6.11.0-rc1-syzkaller-00043-g94ede2a3e913 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024

Fixes: 999cb275c807 ("gtp: add IPv6 support")
Fixes: 459aa660eb1d ("gtp: add initial driver for datapath of GPRS Tunneling Protocol (GTP-U)")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Harald Welte <laforge@gnumonks.org>
---
 drivers/net/gtp.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Pablo Neira Ayuso Aug. 9, 2024, 7:59 a.m. UTC | #1 
On Thu, Aug 08, 2024 at 01:24:55PM +0000, Eric Dumazet wrote:
> syzbot/KMSAN reported use of uninit-value in get_dev_xmit() [1]
> 
> We must make sure the IPv4 or Ipv6 header is pulled in skb->head
> before accessing fields in them.
> 
> Use pskb_inet_may_pull() to fix this issue.
> 
> [1]
> BUG: KMSAN: uninit-value in ipv6_pdp_find drivers/net/gtp.c:220 [inline]
>  BUG: KMSAN: uninit-value in gtp_build_skb_ip6 drivers/net/gtp.c:1229 [inline]
>  BUG: KMSAN: uninit-value in gtp_dev_xmit+0x1424/0x2540 drivers/net/gtp.c:1281
>   ipv6_pdp_find drivers/net/gtp.c:220 [inline]
>   gtp_build_skb_ip6 drivers/net/gtp.c:1229 [inline]
>   gtp_dev_xmit+0x1424/0x2540 drivers/net/gtp.c:1281
>   __netdev_start_xmit include/linux/netdevice.h:4913 [inline]
>   netdev_start_xmit include/linux/netdevice.h:4922 [inline]
>   xmit_one net/core/dev.c:3580 [inline]
>   dev_hard_start_xmit+0x247/0xa20 net/core/dev.c:3596
>   __dev_queue_xmit+0x358c/0x5610 net/core/dev.c:4423
>   dev_queue_xmit include/linux/netdevice.h:3105 [inline]
>   packet_xmit+0x9c/0x6c0 net/packet/af_packet.c:276
>   packet_snd net/packet/af_packet.c:3145 [inline]
>   packet_sendmsg+0x90e3/0xa3a0 net/packet/af_packet.c:3177
>   sock_sendmsg_nosec net/socket.c:730 [inline]
>   __sock_sendmsg+0x30f/0x380 net/socket.c:745
>   __sys_sendto+0x685/0x830 net/socket.c:2204
>   __do_sys_sendto net/socket.c:2216 [inline]
>   __se_sys_sendto net/socket.c:2212 [inline]
>   __x64_sys_sendto+0x125/0x1d0 net/socket.c:2212
>   x64_sys_call+0x3799/0x3c10 arch/x86/include/generated/asm/syscalls_64.h:45
>   do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>   do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
> 
> Uninit was created at:
>   slab_post_alloc_hook mm/slub.c:3994 [inline]
>   slab_alloc_node mm/slub.c:4037 [inline]
>   kmem_cache_alloc_node_noprof+0x6bf/0xb80 mm/slub.c:4080
>   kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:583
>   __alloc_skb+0x363/0x7b0 net/core/skbuff.c:674
>   alloc_skb include/linux/skbuff.h:1320 [inline]
>   alloc_skb_with_frags+0xc8/0xbf0 net/core/skbuff.c:6526
>   sock_alloc_send_pskb+0xa81/0xbf0 net/core/sock.c:2815
>   packet_alloc_skb net/packet/af_packet.c:2994 [inline]
>   packet_snd net/packet/af_packet.c:3088 [inline]
>   packet_sendmsg+0x749c/0xa3a0 net/packet/af_packet.c:3177
>   sock_sendmsg_nosec net/socket.c:730 [inline]
>   __sock_sendmsg+0x30f/0x380 net/socket.c:745
>   __sys_sendto+0x685/0x830 net/socket.c:2204
>   __do_sys_sendto net/socket.c:2216 [inline]
>   __se_sys_sendto net/socket.c:2212 [inline]
>   __x64_sys_sendto+0x125/0x1d0 net/socket.c:2212
>   x64_sys_call+0x3799/0x3c10 arch/x86/include/generated/asm/syscalls_64.h:45
>   do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>   do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
> 
> CPU: 0 UID: 0 PID: 7115 Comm: syz.1.515 Not tainted 6.11.0-rc1-syzkaller-00043-g94ede2a3e913 #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
> 
> Fixes: 999cb275c807 ("gtp: add IPv6 support")
> Fixes: 459aa660eb1d ("gtp: add initial driver for datapath of GPRS Tunneling Protocol (GTP-U)")
> Signed-off-by: Eric Dumazet <edumazet@google.com>

Reviewed-by: Pablo Neira Ayuso <pablo@netfilter.org>

Thanks.
patchwork-bot+netdevbpf@kernel.org Aug. 10, 2024, 5:10 a.m. UTC | #2 
Hello:

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

On Thu,  8 Aug 2024 13:24:55 +0000 you wrote:
> syzbot/KMSAN reported use of uninit-value in get_dev_xmit() [1]
> 
> We must make sure the IPv4 or Ipv6 header is pulled in skb->head
> before accessing fields in them.
> 
> Use pskb_inet_may_pull() to fix this issue.
> 
> [...]

Here is the summary with links:
  - [net] gtp: pull network headers in gtp_dev_xmit()
    https://git.kernel.org/netdev/net/c/3a3be7ff9224

You are awesome, thank you!
diff mbox series

Patch

diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c
index 427b91aca50d3a370e4ad00071f0c477fefa5076..0696faf60013e0669ceb4aa39dfbac17ad741540 100644
--- a/drivers/net/gtp.c
+++ b/drivers/net/gtp.c
@@ -1269,6 +1269,9 @@  static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev)
 	if (skb_cow_head(skb, dev->needed_headroom))
 		goto tx_err;
 
+	if (!pskb_inet_may_pull(skb))
+		goto tx_err;
+
 	skb_reset_inner_headers(skb);
 
 	/* PDP context lookups in gtp_build_skb_*() need rcu read-side lock. */