* [PATCH 5.15 1/2] netlink: annotate lockless accesses to nlk->max_recvmsg_len
2024-05-15 7:36 [PATCH 5.15 0/2] netlink, fix issues caught by syzbot Yenchia Chen
@ 2024-05-15 7:36 ` Yenchia Chen
2024-05-15 17:44 ` Carlos Llamas
2024-05-15 7:36 ` [PATCH 5.15 2/2] netlink: annotate data-races around sk->sk_err Yenchia Chen
2024-05-23 11:51 ` [PATCH 5.15 0/2] netlink, fix issues caught by syzbot Greg KH
2 siblings, 1 reply; 6+ messages in thread
From: Yenchia Chen @ 2024-05-15 7:36 UTC (permalink / raw)
To: stable
Cc: Eric Dumazet, Jakub Kicinski, yenchia . chen, David S. Miller,
Matthias Brugger, Sasha Levin, Simon Horman, Ryosuke Yasuoka,
Zhengchao Shao, Pedro Tammela, Thomas Graf, netdev, linux-kernel,
linux-arm-kernel, linux-mediatek
From: Eric Dumazet <edumazet@google.com>
syzbot reported a data-race in data-race in netlink_recvmsg() [1]
Indeed, netlink_recvmsg() can be run concurrently,
and netlink_dump() also needs protection.
[1]
BUG: KCSAN: data-race in netlink_recvmsg / netlink_recvmsg
read to 0xffff888141840b38 of 8 bytes by task 23057 on cpu 0:
netlink_recvmsg+0xea/0x730 net/netlink/af_netlink.c:1988
sock_recvmsg_nosec net/socket.c:1017 [inline]
sock_recvmsg net/socket.c:1038 [inline]
__sys_recvfrom+0x1ee/0x2e0 net/socket.c:2194
__do_sys_recvfrom net/socket.c:2212 [inline]
__se_sys_recvfrom net/socket.c:2208 [inline]
__x64_sys_recvfrom+0x78/0x90 net/socket.c:2208
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
write to 0xffff888141840b38 of 8 bytes by task 23037 on cpu 1:
netlink_recvmsg+0x114/0x730 net/netlink/af_netlink.c:1989
sock_recvmsg_nosec net/socket.c:1017 [inline]
sock_recvmsg net/socket.c:1038 [inline]
____sys_recvmsg+0x156/0x310 net/socket.c:2720
___sys_recvmsg net/socket.c:2762 [inline]
do_recvmmsg+0x2e5/0x710 net/socket.c:2856
__sys_recvmmsg net/socket.c:2935 [inline]
__do_sys_recvmmsg net/socket.c:2958 [inline]
__se_sys_recvmmsg net/socket.c:2951 [inline]
__x64_sys_recvmmsg+0xe2/0x160 net/socket.c:2951
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
value changed: 0x0000000000000000 -> 0x0000000000001000
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 23037 Comm: syz-executor.2 Not tainted 6.3.0-rc4-syzkaller-00195-g5a57b48fdfcb #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
Fixes: 9063e21fb026 ("netlink: autosize skb lengthes")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/20230403214643.768555-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: yenchia.chen <yenchia.chen@mediatek.com>
---
net/netlink/af_netlink.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 82df02695bbd..56ba8a6396ca 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1935,7 +1935,7 @@ static int netlink_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
struct sock *sk = sock->sk;
struct netlink_sock *nlk = nlk_sk(sk);
int noblock = flags & MSG_DONTWAIT;
- size_t copied;
+ size_t copied, max_recvmsg_len;
struct sk_buff *skb, *data_skb;
int err, ret;
@@ -1968,9 +1968,10 @@ static int netlink_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
#endif
/* Record the max length of recvmsg() calls for future allocations */
- nlk->max_recvmsg_len = max(nlk->max_recvmsg_len, len);
- nlk->max_recvmsg_len = min_t(size_t, nlk->max_recvmsg_len,
- SKB_WITH_OVERHEAD(32768));
+ max_recvmsg_len = max(READ_ONCE(nlk->max_recvmsg_len), len);
+ max_recvmsg_len = min_t(size_t, max_recvmsg_len,
+ SKB_WITH_OVERHEAD(32768));
+ WRITE_ONCE(nlk->max_recvmsg_len, max_recvmsg_len);
copied = data_skb->len;
if (len < copied) {
@@ -2219,6 +2220,7 @@ static int netlink_dump(struct sock *sk)
struct netlink_ext_ack extack = {};
struct netlink_callback *cb;
struct sk_buff *skb = NULL;
+ size_t max_recvmsg_len;
struct module *module;
int err = -ENOBUFS;
int alloc_min_size;
@@ -2241,8 +2243,9 @@ static int netlink_dump(struct sock *sk)
cb = &nlk->cb;
alloc_min_size = max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE);
- if (alloc_min_size < nlk->max_recvmsg_len) {
- alloc_size = nlk->max_recvmsg_len;
+ max_recvmsg_len = READ_ONCE(nlk->max_recvmsg_len);
+ if (alloc_min_size < max_recvmsg_len) {
+ alloc_size = max_recvmsg_len;
skb = alloc_skb(alloc_size,
(GFP_KERNEL & ~__GFP_DIRECT_RECLAIM) |
__GFP_NOWARN | __GFP_NORETRY);
--
2.18.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH 5.15 1/2] netlink: annotate lockless accesses to nlk->max_recvmsg_len
2024-05-15 7:36 ` [PATCH 5.15 1/2] netlink: annotate lockless accesses to nlk->max_recvmsg_len Yenchia Chen
@ 2024-05-15 17:44 ` Carlos Llamas
0 siblings, 0 replies; 6+ messages in thread
From: Carlos Llamas @ 2024-05-15 17:44 UTC (permalink / raw)
To: Yenchia Chen
Cc: stable, Eric Dumazet, Jakub Kicinski, David S. Miller,
Matthias Brugger, Sasha Levin, Simon Horman, Ryosuke Yasuoka,
Zhengchao Shao, Pedro Tammela, Thomas Graf, netdev, linux-kernel,
linux-arm-kernel, linux-mediatek
On Wed, May 15, 2024 at 03:36:37PM +0800, Yenchia Chen wrote:
> From: Eric Dumazet <edumazet@google.com>
>
> syzbot reported a data-race in data-race in netlink_recvmsg() [1]
>
> Indeed, netlink_recvmsg() can be run concurrently,
> and netlink_dump() also needs protection.
>
> [1]
> BUG: KCSAN: data-race in netlink_recvmsg / netlink_recvmsg
>
> read to 0xffff888141840b38 of 8 bytes by task 23057 on cpu 0:
> netlink_recvmsg+0xea/0x730 net/netlink/af_netlink.c:1988
> sock_recvmsg_nosec net/socket.c:1017 [inline]
> sock_recvmsg net/socket.c:1038 [inline]
> __sys_recvfrom+0x1ee/0x2e0 net/socket.c:2194
> __do_sys_recvfrom net/socket.c:2212 [inline]
> __se_sys_recvfrom net/socket.c:2208 [inline]
> __x64_sys_recvfrom+0x78/0x90 net/socket.c:2208
> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
> do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
> entry_SYSCALL_64_after_hwframe+0x63/0xcd
>
> write to 0xffff888141840b38 of 8 bytes by task 23037 on cpu 1:
> netlink_recvmsg+0x114/0x730 net/netlink/af_netlink.c:1989
> sock_recvmsg_nosec net/socket.c:1017 [inline]
> sock_recvmsg net/socket.c:1038 [inline]
> ____sys_recvmsg+0x156/0x310 net/socket.c:2720
> ___sys_recvmsg net/socket.c:2762 [inline]
> do_recvmmsg+0x2e5/0x710 net/socket.c:2856
> __sys_recvmmsg net/socket.c:2935 [inline]
> __do_sys_recvmmsg net/socket.c:2958 [inline]
> __se_sys_recvmmsg net/socket.c:2951 [inline]
> __x64_sys_recvmmsg+0xe2/0x160 net/socket.c:2951
> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
> do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
> entry_SYSCALL_64_after_hwframe+0x63/0xcd
>
> value changed: 0x0000000000000000 -> 0x0000000000001000
>
> Reported by Kernel Concurrency Sanitizer on:
> CPU: 1 PID: 23037 Comm: syz-executor.2 Not tainted 6.3.0-rc4-syzkaller-00195-g5a57b48fdfcb #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
>
> Fixes: 9063e21fb026 ("netlink: autosize skb lengthes")
> Reported-by: syzbot <syzkaller@googlegroups.com>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Reviewed-by: Simon Horman <simon.horman@corigine.com>
> Link: https://lore.kernel.org/r/20230403214643.768555-1-edumazet@google.com
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
> Signed-off-by: yenchia.chen <yenchia.chen@mediatek.com>
> ---
The conflict resolution looks good to me, thanks!
Reviewed-by: Carlos Llamas <cmllamas@google.com>
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 5.15 2/2] netlink: annotate data-races around sk->sk_err
2024-05-15 7:36 [PATCH 5.15 0/2] netlink, fix issues caught by syzbot Yenchia Chen
2024-05-15 7:36 ` [PATCH 5.15 1/2] netlink: annotate lockless accesses to nlk->max_recvmsg_len Yenchia Chen
@ 2024-05-15 7:36 ` Yenchia Chen
2024-05-15 17:45 ` Carlos Llamas
2024-05-23 11:51 ` [PATCH 5.15 0/2] netlink, fix issues caught by syzbot Greg KH
2 siblings, 1 reply; 6+ messages in thread
From: Yenchia Chen @ 2024-05-15 7:36 UTC (permalink / raw)
To: stable
Cc: Eric Dumazet, Jakub Kicinski, yenchia . chen, David S. Miller,
Matthias Brugger, Sasha Levin, Simon Horman, Zhengchao Shao,
Pedro Tammela, Ryosuke Yasuoka, Thomas Graf, netdev, linux-kernel,
linux-arm-kernel, linux-mediatek
From: Eric Dumazet <edumazet@google.com>
syzbot caught another data-race in netlink when
setting sk->sk_err.
Annotate all of them for good measure.
BUG: KCSAN: data-race in netlink_recvmsg / netlink_recvmsg
write to 0xffff8881613bb220 of 4 bytes by task 28147 on cpu 0:
netlink_recvmsg+0x448/0x780 net/netlink/af_netlink.c:1994
sock_recvmsg_nosec net/socket.c:1027 [inline]
sock_recvmsg net/socket.c:1049 [inline]
__sys_recvfrom+0x1f4/0x2e0 net/socket.c:2229
__do_sys_recvfrom net/socket.c:2247 [inline]
__se_sys_recvfrom net/socket.c:2243 [inline]
__x64_sys_recvfrom+0x78/0x90 net/socket.c:2243
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
write to 0xffff8881613bb220 of 4 bytes by task 28146 on cpu 1:
netlink_recvmsg+0x448/0x780 net/netlink/af_netlink.c:1994
sock_recvmsg_nosec net/socket.c:1027 [inline]
sock_recvmsg net/socket.c:1049 [inline]
__sys_recvfrom+0x1f4/0x2e0 net/socket.c:2229
__do_sys_recvfrom net/socket.c:2247 [inline]
__se_sys_recvfrom net/socket.c:2243 [inline]
__x64_sys_recvfrom+0x78/0x90 net/socket.c:2243
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
value changed: 0x00000000 -> 0x00000016
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 28146 Comm: syz-executor.0 Not tainted 6.6.0-rc3-syzkaller-00055-g9ed22ae6be81 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20231003183455.3410550-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: yenchia.chen <yenchia.chen@mediatek.com>
---
net/netlink/af_netlink.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 56ba8a6396ca..216445dd44db 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -352,7 +352,7 @@ static void netlink_overrun(struct sock *sk)
if (!(nlk->flags & NETLINK_F_RECV_NO_ENOBUFS)) {
if (!test_and_set_bit(NETLINK_S_CONGESTED,
&nlk_sk(sk)->state)) {
- sk->sk_err = ENOBUFS;
+ WRITE_ONCE(sk->sk_err, ENOBUFS);
sk_error_report(sk);
}
}
@@ -1591,7 +1591,7 @@ static int do_one_set_err(struct sock *sk, struct netlink_set_err_data *p)
goto out;
}
- sk->sk_err = p->code;
+ WRITE_ONCE(sk->sk_err, p->code);
sk_error_report(sk);
out:
return ret;
@@ -2006,7 +2006,7 @@ static int netlink_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) {
ret = netlink_dump(sk);
if (ret) {
- sk->sk_err = -ret;
+ WRITE_ONCE(sk->sk_err, -ret);
sk_error_report(sk);
}
}
@@ -2442,7 +2442,7 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err,
skb = nlmsg_new(payload + tlvlen, GFP_KERNEL);
if (!skb) {
- NETLINK_CB(in_skb).sk->sk_err = ENOBUFS;
+ WRITE_ONCE(NETLINK_CB(in_skb).sk->sk_err, ENOBUFS);
sk_error_report(NETLINK_CB(in_skb).sk);
return;
}
--
2.18.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH 5.15 2/2] netlink: annotate data-races around sk->sk_err
2024-05-15 7:36 ` [PATCH 5.15 2/2] netlink: annotate data-races around sk->sk_err Yenchia Chen
@ 2024-05-15 17:45 ` Carlos Llamas
0 siblings, 0 replies; 6+ messages in thread
From: Carlos Llamas @ 2024-05-15 17:45 UTC (permalink / raw)
To: Yenchia Chen
Cc: stable, Eric Dumazet, Jakub Kicinski, David S. Miller,
Matthias Brugger, Sasha Levin, Simon Horman, Zhengchao Shao,
Pedro Tammela, Ryosuke Yasuoka, Thomas Graf, netdev, linux-kernel,
linux-arm-kernel, linux-mediatek
On Wed, May 15, 2024 at 03:36:38PM +0800, Yenchia Chen wrote:
> From: Eric Dumazet <edumazet@google.com>
>
> syzbot caught another data-race in netlink when
> setting sk->sk_err.
>
> Annotate all of them for good measure.
>
> BUG: KCSAN: data-race in netlink_recvmsg / netlink_recvmsg
>
> write to 0xffff8881613bb220 of 4 bytes by task 28147 on cpu 0:
> netlink_recvmsg+0x448/0x780 net/netlink/af_netlink.c:1994
> sock_recvmsg_nosec net/socket.c:1027 [inline]
> sock_recvmsg net/socket.c:1049 [inline]
> __sys_recvfrom+0x1f4/0x2e0 net/socket.c:2229
> __do_sys_recvfrom net/socket.c:2247 [inline]
> __se_sys_recvfrom net/socket.c:2243 [inline]
> __x64_sys_recvfrom+0x78/0x90 net/socket.c:2243
> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
> do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
> entry_SYSCALL_64_after_hwframe+0x63/0xcd
>
> write to 0xffff8881613bb220 of 4 bytes by task 28146 on cpu 1:
> netlink_recvmsg+0x448/0x780 net/netlink/af_netlink.c:1994
> sock_recvmsg_nosec net/socket.c:1027 [inline]
> sock_recvmsg net/socket.c:1049 [inline]
> __sys_recvfrom+0x1f4/0x2e0 net/socket.c:2229
> __do_sys_recvfrom net/socket.c:2247 [inline]
> __se_sys_recvfrom net/socket.c:2243 [inline]
> __x64_sys_recvfrom+0x78/0x90 net/socket.c:2243
> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
> do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
> entry_SYSCALL_64_after_hwframe+0x63/0xcd
>
> value changed: 0x00000000 -> 0x00000016
>
> Reported by Kernel Concurrency Sanitizer on:
> CPU: 1 PID: 28146 Comm: syz-executor.0 Not tainted 6.6.0-rc3-syzkaller-00055-g9ed22ae6be81 #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
>
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Reported-by: syzbot <syzkaller@googlegroups.com>
> Reviewed-by: Simon Horman <horms@kernel.org>
> Link: https://lore.kernel.org/r/20231003183455.3410550-1-edumazet@google.com
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
> Signed-off-by: yenchia.chen <yenchia.chen@mediatek.com>
> ---
The conflict resolution looks good to me, thanks!
Reviewed-by: Carlos Llamas <cmllamas@google.com>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 5.15 0/2] netlink, fix issues caught by syzbot
2024-05-15 7:36 [PATCH 5.15 0/2] netlink, fix issues caught by syzbot Yenchia Chen
2024-05-15 7:36 ` [PATCH 5.15 1/2] netlink: annotate lockless accesses to nlk->max_recvmsg_len Yenchia Chen
2024-05-15 7:36 ` [PATCH 5.15 2/2] netlink: annotate data-races around sk->sk_err Yenchia Chen
@ 2024-05-23 11:51 ` Greg KH
2 siblings, 0 replies; 6+ messages in thread
From: Greg KH @ 2024-05-23 11:51 UTC (permalink / raw)
To: Yenchia Chen
Cc: stable, David S. Miller, Jakub Kicinski, Matthias Brugger,
Eric Dumazet, Sasha Levin, Simon Horman, Pedro Tammela,
Zhengchao Shao, Ryosuke Yasuoka, Thomas Graf, netdev,
linux-kernel, linux-arm-kernel, linux-mediatek
On Wed, May 15, 2024 at 03:36:36PM +0800, Yenchia Chen wrote:
> From: "yenchia.chen" <yenchia.chen@mediatek.com>
>
> Hi,
>
> We think 5.15.y could pick these commits.
>
> Below is the mainline commit:
>
> netlink: annotate lockless accesses to nlk->max_recvmsg_len
> [ Upstream commit a1865f2e7d10dde00d35a2122b38d2e469ae67ed ]
>
> netlink: annotate data-races around sk->sk_err
> [ Upstream commit d0f95894fda7d4f895b29c1097f92d7fee278cb2 ]
>
> Eric Dumazet (2):
> netlink: annotate lockless accesses to nlk->max_recvmsg_len
> netlink: annotate data-races around sk->sk_err
>
> net/netlink/af_netlink.c | 23 +++++++++++++----------
> 1 file changed, 13 insertions(+), 10 deletions(-)
>
> --
> 2.18.0
>
>
All now queued up, thanks.
greg k-h
^ permalink raw reply [flat|nested] 6+ messages in thread