diff mbox series

[net] sched: act_ct: take care of padding in struct zones_ht_key

Message ID 20240725092745.1760161-1-edumazet@google.com (mailing list archive)
State Accepted
Commit 2191a54f63225b548fd8346be3611c3219a24738
Delegated to: Netdev Maintainers
Headers show
Series [net] sched: act_ct: take care of padding in struct zones_ht_key | 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: 273 this patch: 273
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers fail 1 blamed authors not CCed: horms@kernel.org; 1 maintainers not CCed: horms@kernel.org
netdev/build_clang success Errors and warnings before: 281 this patch: 281
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: 281 this patch: 281
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 16 lines checked
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-2024-07-25--15-00 (tests: 701)

Commit Message

Eric Dumazet July 25, 2024, 9:27 a.m. UTC 
Blamed commit increased lookup key size from 2 bytes to 16 bytes,
because zones_ht_key got a struct net pointer.

Make sure rhashtable_lookup() is not using the padding bytes
which are not initialized.

 BUG: KMSAN: uninit-value in rht_ptr_rcu include/linux/rhashtable.h:376 [inline]
 BUG: KMSAN: uninit-value in __rhashtable_lookup include/linux/rhashtable.h:607 [inline]
 BUG: KMSAN: uninit-value in rhashtable_lookup include/linux/rhashtable.h:646 [inline]
 BUG: KMSAN: uninit-value in rhashtable_lookup_fast include/linux/rhashtable.h:672 [inline]
 BUG: KMSAN: uninit-value in tcf_ct_flow_table_get+0x611/0x2260 net/sched/act_ct.c:329
  rht_ptr_rcu include/linux/rhashtable.h:376 [inline]
  __rhashtable_lookup include/linux/rhashtable.h:607 [inline]
  rhashtable_lookup include/linux/rhashtable.h:646 [inline]
  rhashtable_lookup_fast include/linux/rhashtable.h:672 [inline]
  tcf_ct_flow_table_get+0x611/0x2260 net/sched/act_ct.c:329
  tcf_ct_init+0xa67/0x2890 net/sched/act_ct.c:1408
  tcf_action_init_1+0x6cc/0xb30 net/sched/act_api.c:1425
  tcf_action_init+0x458/0xf00 net/sched/act_api.c:1488
  tcf_action_add net/sched/act_api.c:2061 [inline]
  tc_ctl_action+0x4be/0x19d0 net/sched/act_api.c:2118
  rtnetlink_rcv_msg+0x12fc/0x1410 net/core/rtnetlink.c:6647
  netlink_rcv_skb+0x375/0x650 net/netlink/af_netlink.c:2550
  rtnetlink_rcv+0x34/0x40 net/core/rtnetlink.c:6665
  netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
  netlink_unicast+0xf52/0x1260 net/netlink/af_netlink.c:1357
  netlink_sendmsg+0x10da/0x11e0 net/netlink/af_netlink.c:1901
  sock_sendmsg_nosec net/socket.c:730 [inline]
  __sock_sendmsg+0x30f/0x380 net/socket.c:745
  ____sys_sendmsg+0x877/0xb60 net/socket.c:2597
  ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2651
  __sys_sendmsg net/socket.c:2680 [inline]
  __do_sys_sendmsg net/socket.c:2689 [inline]
  __se_sys_sendmsg net/socket.c:2687 [inline]
  __x64_sys_sendmsg+0x307/0x4a0 net/socket.c:2687
  x64_sys_call+0x2dd6/0x3c10 arch/x86/include/generated/asm/syscalls_64.h:47
  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

Local variable key created at:
  tcf_ct_flow_table_get+0x4a/0x2260 net/sched/act_ct.c:324
  tcf_ct_init+0xa67/0x2890 net/sched/act_ct.c:1408

Fixes: 88c67aeb1407 ("sched: act_ct: add netns into the key of tcf_ct_flow_table")
Reported-by: syzbot+1b5e4e187cc586d05ea0@syzkaller.appspotmail.com
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Xin Long <lucien.xin@gmail.com>
---
 net/sched/act_ct.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Comments

Simon Horman July 25, 2024, 10:03 a.m. UTC | #1 
On Thu, Jul 25, 2024 at 09:27:45AM +0000, Eric Dumazet wrote:
> Blamed commit increased lookup key size from 2 bytes to 16 bytes,
> because zones_ht_key got a struct net pointer.
> 
> Make sure rhashtable_lookup() is not using the padding bytes
> which are not initialized.
> 
>  BUG: KMSAN: uninit-value in rht_ptr_rcu include/linux/rhashtable.h:376 [inline]
>  BUG: KMSAN: uninit-value in __rhashtable_lookup include/linux/rhashtable.h:607 [inline]
>  BUG: KMSAN: uninit-value in rhashtable_lookup include/linux/rhashtable.h:646 [inline]
>  BUG: KMSAN: uninit-value in rhashtable_lookup_fast include/linux/rhashtable.h:672 [inline]
>  BUG: KMSAN: uninit-value in tcf_ct_flow_table_get+0x611/0x2260 net/sched/act_ct.c:329
>   rht_ptr_rcu include/linux/rhashtable.h:376 [inline]
>   __rhashtable_lookup include/linux/rhashtable.h:607 [inline]
>   rhashtable_lookup include/linux/rhashtable.h:646 [inline]
>   rhashtable_lookup_fast include/linux/rhashtable.h:672 [inline]
>   tcf_ct_flow_table_get+0x611/0x2260 net/sched/act_ct.c:329
>   tcf_ct_init+0xa67/0x2890 net/sched/act_ct.c:1408
>   tcf_action_init_1+0x6cc/0xb30 net/sched/act_api.c:1425
>   tcf_action_init+0x458/0xf00 net/sched/act_api.c:1488
>   tcf_action_add net/sched/act_api.c:2061 [inline]
>   tc_ctl_action+0x4be/0x19d0 net/sched/act_api.c:2118
>   rtnetlink_rcv_msg+0x12fc/0x1410 net/core/rtnetlink.c:6647
>   netlink_rcv_skb+0x375/0x650 net/netlink/af_netlink.c:2550
>   rtnetlink_rcv+0x34/0x40 net/core/rtnetlink.c:6665
>   netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
>   netlink_unicast+0xf52/0x1260 net/netlink/af_netlink.c:1357
>   netlink_sendmsg+0x10da/0x11e0 net/netlink/af_netlink.c:1901
>   sock_sendmsg_nosec net/socket.c:730 [inline]
>   __sock_sendmsg+0x30f/0x380 net/socket.c:745
>   ____sys_sendmsg+0x877/0xb60 net/socket.c:2597
>   ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2651
>   __sys_sendmsg net/socket.c:2680 [inline]
>   __do_sys_sendmsg net/socket.c:2689 [inline]
>   __se_sys_sendmsg net/socket.c:2687 [inline]
>   __x64_sys_sendmsg+0x307/0x4a0 net/socket.c:2687
>   x64_sys_call+0x2dd6/0x3c10 arch/x86/include/generated/asm/syscalls_64.h:47
>   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
> 
> Local variable key created at:
>   tcf_ct_flow_table_get+0x4a/0x2260 net/sched/act_ct.c:324
>   tcf_ct_init+0xa67/0x2890 net/sched/act_ct.c:1408
> 
> Fixes: 88c67aeb1407 ("sched: act_ct: add netns into the key of tcf_ct_flow_table")
> Reported-by: syzbot+1b5e4e187cc586d05ea0@syzkaller.appspotmail.com
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Cc: Xin Long <lucien.xin@gmail.com>

Reviewed-by: Simon Horman <horms@kernel.org>
Xin Long July 25, 2024, 2:30 p.m. UTC | #2 
On Thu, Jul 25, 2024 at 5:27 AM Eric Dumazet <edumazet@google.com> wrote:
>
> Blamed commit increased lookup key size from 2 bytes to 16 bytes,
> because zones_ht_key got a struct net pointer.
>
> Make sure rhashtable_lookup() is not using the padding bytes
> which are not initialized.
>
>  BUG: KMSAN: uninit-value in rht_ptr_rcu include/linux/rhashtable.h:376 [inline]
>  BUG: KMSAN: uninit-value in __rhashtable_lookup include/linux/rhashtable.h:607 [inline]
>  BUG: KMSAN: uninit-value in rhashtable_lookup include/linux/rhashtable.h:646 [inline]
>  BUG: KMSAN: uninit-value in rhashtable_lookup_fast include/linux/rhashtable.h:672 [inline]
>  BUG: KMSAN: uninit-value in tcf_ct_flow_table_get+0x611/0x2260 net/sched/act_ct.c:329
>   rht_ptr_rcu include/linux/rhashtable.h:376 [inline]
>   __rhashtable_lookup include/linux/rhashtable.h:607 [inline]
>   rhashtable_lookup include/linux/rhashtable.h:646 [inline]
>   rhashtable_lookup_fast include/linux/rhashtable.h:672 [inline]
>   tcf_ct_flow_table_get+0x611/0x2260 net/sched/act_ct.c:329
>   tcf_ct_init+0xa67/0x2890 net/sched/act_ct.c:1408
>   tcf_action_init_1+0x6cc/0xb30 net/sched/act_api.c:1425
>   tcf_action_init+0x458/0xf00 net/sched/act_api.c:1488
>   tcf_action_add net/sched/act_api.c:2061 [inline]
>   tc_ctl_action+0x4be/0x19d0 net/sched/act_api.c:2118
>   rtnetlink_rcv_msg+0x12fc/0x1410 net/core/rtnetlink.c:6647
>   netlink_rcv_skb+0x375/0x650 net/netlink/af_netlink.c:2550
>   rtnetlink_rcv+0x34/0x40 net/core/rtnetlink.c:6665
>   netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
>   netlink_unicast+0xf52/0x1260 net/netlink/af_netlink.c:1357
>   netlink_sendmsg+0x10da/0x11e0 net/netlink/af_netlink.c:1901
>   sock_sendmsg_nosec net/socket.c:730 [inline]
>   __sock_sendmsg+0x30f/0x380 net/socket.c:745
>   ____sys_sendmsg+0x877/0xb60 net/socket.c:2597
>   ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2651
>   __sys_sendmsg net/socket.c:2680 [inline]
>   __do_sys_sendmsg net/socket.c:2689 [inline]
>   __se_sys_sendmsg net/socket.c:2687 [inline]
>   __x64_sys_sendmsg+0x307/0x4a0 net/socket.c:2687
>   x64_sys_call+0x2dd6/0x3c10 arch/x86/include/generated/asm/syscalls_64.h:47
>   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
>
> Local variable key created at:
>   tcf_ct_flow_table_get+0x4a/0x2260 net/sched/act_ct.c:324
>   tcf_ct_init+0xa67/0x2890 net/sched/act_ct.c:1408
>
> Fixes: 88c67aeb1407 ("sched: act_ct: add netns into the key of tcf_ct_flow_table")
> Reported-by: syzbot+1b5e4e187cc586d05ea0@syzkaller.appspotmail.com
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Cc: Xin Long <lucien.xin@gmail.com>

Reviewed-by: Xin Long <lucien.xin@gmail.com>

Thanks, didn't know this doesn't get padding bytes initialized:

struct zones_ht_key key = { .net = net, .zone = params->zone };
patchwork-bot+netdevbpf@kernel.org July 26, 2024, 10:30 a.m. UTC | #3 
Hello:

This patch was applied to netdev/net.git (main)
by David S. Miller <davem@davemloft.net>:

On Thu, 25 Jul 2024 09:27:45 +0000 you wrote:
> Blamed commit increased lookup key size from 2 bytes to 16 bytes,
> because zones_ht_key got a struct net pointer.
> 
> Make sure rhashtable_lookup() is not using the padding bytes
> which are not initialized.
> 
>  BUG: KMSAN: uninit-value in rht_ptr_rcu include/linux/rhashtable.h:376 [inline]
>  BUG: KMSAN: uninit-value in __rhashtable_lookup include/linux/rhashtable.h:607 [inline]
>  BUG: KMSAN: uninit-value in rhashtable_lookup include/linux/rhashtable.h:646 [inline]
>  BUG: KMSAN: uninit-value in rhashtable_lookup_fast include/linux/rhashtable.h:672 [inline]
>  BUG: KMSAN: uninit-value in tcf_ct_flow_table_get+0x611/0x2260 net/sched/act_ct.c:329
>   rht_ptr_rcu include/linux/rhashtable.h:376 [inline]
>   __rhashtable_lookup include/linux/rhashtable.h:607 [inline]
>   rhashtable_lookup include/linux/rhashtable.h:646 [inline]
>   rhashtable_lookup_fast include/linux/rhashtable.h:672 [inline]
>   tcf_ct_flow_table_get+0x611/0x2260 net/sched/act_ct.c:329
>   tcf_ct_init+0xa67/0x2890 net/sched/act_ct.c:1408
>   tcf_action_init_1+0x6cc/0xb30 net/sched/act_api.c:1425
>   tcf_action_init+0x458/0xf00 net/sched/act_api.c:1488
>   tcf_action_add net/sched/act_api.c:2061 [inline]
>   tc_ctl_action+0x4be/0x19d0 net/sched/act_api.c:2118
>   rtnetlink_rcv_msg+0x12fc/0x1410 net/core/rtnetlink.c:6647
>   netlink_rcv_skb+0x375/0x650 net/netlink/af_netlink.c:2550
>   rtnetlink_rcv+0x34/0x40 net/core/rtnetlink.c:6665
>   netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
>   netlink_unicast+0xf52/0x1260 net/netlink/af_netlink.c:1357
>   netlink_sendmsg+0x10da/0x11e0 net/netlink/af_netlink.c:1901
>   sock_sendmsg_nosec net/socket.c:730 [inline]
>   __sock_sendmsg+0x30f/0x380 net/socket.c:745
>   ____sys_sendmsg+0x877/0xb60 net/socket.c:2597
>   ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2651
>   __sys_sendmsg net/socket.c:2680 [inline]
>   __do_sys_sendmsg net/socket.c:2689 [inline]
>   __se_sys_sendmsg net/socket.c:2687 [inline]
>   __x64_sys_sendmsg+0x307/0x4a0 net/socket.c:2687
>   x64_sys_call+0x2dd6/0x3c10 arch/x86/include/generated/asm/syscalls_64.h:47
>   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
> 
> [...]

Here is the summary with links:
  - [net] sched: act_ct: take care of padding in struct zones_ht_key
    https://git.kernel.org/netdev/net/c/2191a54f6322

You are awesome, thank you!
diff mbox series

Patch

diff --git a/net/sched/act_ct.c b/net/sched/act_ct.c
index 113b907da0f757af7be920cc9b3a1b1c769f5804..3ba8e7e739b58a96e66ca64d38bff758500df3e1 100644
--- a/net/sched/act_ct.c
+++ b/net/sched/act_ct.c
@@ -44,6 +44,8 @@  static DEFINE_MUTEX(zones_mutex);
 struct zones_ht_key {
 	struct net *net;
 	u16 zone;
+	/* Note : pad[] must be the last field. */
+	u8  pad[];
 };
 
 struct tcf_ct_flow_table {
@@ -60,7 +62,7 @@  struct tcf_ct_flow_table {
 static const struct rhashtable_params zones_params = {
 	.head_offset = offsetof(struct tcf_ct_flow_table, node),
 	.key_offset = offsetof(struct tcf_ct_flow_table, key),
-	.key_len = sizeof_field(struct tcf_ct_flow_table, key),
+	.key_len = offsetof(struct zones_ht_key, pad),
 	.automatic_shrinking = true,
 };