* [syzbot] general protection fault in smc_tx_sendmsg
@ 2021-06-20 23:22 syzbot
2021-06-21 14:56 ` Pavel Skripkin
0 siblings, 1 reply; 4+ messages in thread
From: syzbot @ 2021-06-20 23:22 UTC (permalink / raw)
To: coreteam, davem, dsahern, fw, kadlec, kgraul, kuba, linux-kernel,
linux-s390, netdev, netfilter-devel, pablo, syzkaller-bugs,
yoshfuji
Hello,
syzbot found the following issue on:
HEAD commit: 0c337952 Merge tag 'wireless-drivers-next-2021-06-16' of g..
git tree: net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1621de10300000
kernel config: https://syzkaller.appspot.com/x/.config?x=a6380da8984033f1
dashboard link: https://syzkaller.appspot.com/bug?extid=5dda108b672b54141857
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=121d2d20300000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=100bd768300000
The issue was bisected to:
commit f9006acc8dfe59e25aa75729728ac57a8d84fc32
Author: Florian Westphal <fw@strlen.de>
Date: Wed Apr 21 07:51:08 2021 +0000
netfilter: arp_tables: pass table pointer via nf_hook_ops
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=12600fffd00000
final oops: https://syzkaller.appspot.com/x/report.txt?x=11600fffd00000
console output: https://syzkaller.appspot.com/x/log.txt?x=16600fffd00000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5dda108b672b54141857@syzkaller.appspotmail.com
Fixes: f9006acc8dfe ("netfilter: arp_tables: pass table pointer via nf_hook_ops")
general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]
CPU: 1 PID: 8455 Comm: syz-executor893 Not tainted 5.13.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:smc_tx_sendmsg+0x204/0x1ba0 net/smc/smc_tx.c:157
Code: 48 c1 ea 03 80 3c 02 00 0f 85 8b 17 00 00 49 8b 9d 08 05 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 20 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e 8f 17 00 00 48 63 5b 20 4c 8b
RSP: 0018:ffffc9000164f800 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000004 RSI: ffffffff889cd6ae RDI: 0000000000000020
RBP: ffff88801cf58000 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff889cd6a1 R11: 0000000000000000 R12: 0000000000000000
R13: ffff88801cf58000 R14: ffffc9000164fd90 R15: ffff88801cf58060
FS: 0000000000ebf300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd43ca1328 CR3: 000000002acf2000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
smc_sendmsg+0x274/0x5b0 net/smc/af_smc.c:2037
sock_sendmsg_nosec net/socket.c:654 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:674
____sys_sendmsg+0x331/0x810 net/socket.c:2350
___sys_sendmsg+0xf3/0x170 net/socket.c:2404
__sys_sendmmsg+0x195/0x470 net/socket.c:2490
__do_sys_sendmmsg net/socket.c:2519 [inline]
__se_sys_sendmmsg net/socket.c:2516 [inline]
__x64_sys_sendmmsg+0x99/0x100 net/socket.c:2516
do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x43ee89
Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc82b20a58 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 0000000000400488 RCX: 000000000043ee89
RDX: 0000000000000001 RSI: 0000000020003d80 RDI: 0000000000000003
RBP: 0000000000402e70 R08: 0000000000000000 R09: 0000000000400488
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402f00
R13: 0000000000000000 R14: 00000000004ac018 R15: 0000000000400488
Modules linked in:
---[ end trace 459b28282ae53115 ]---
RIP: 0010:smc_tx_sendmsg+0x204/0x1ba0 net/smc/smc_tx.c:157
Code: 48 c1 ea 03 80 3c 02 00 0f 85 8b 17 00 00 49 8b 9d 08 05 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 20 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e 8f 17 00 00 48 63 5b 20 4c 8b
RSP: 0018:ffffc9000164f800 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000004 RSI: ffffffff889cd6ae RDI: 0000000000000020
RBP: ffff88801cf58000 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff889cd6a1 R11: 0000000000000000 R12: 0000000000000000
R13: ffff88801cf58000 R14: ffffc9000164fd90 R15: ffff88801cf58060
FS: 0000000000ebf300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b7501be298 CR3: 000000002acf2000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [syzbot] general protection fault in smc_tx_sendmsg 2021-06-20 23:22 [syzbot] general protection fault in smc_tx_sendmsg syzbot @ 2021-06-21 14:56 ` Pavel Skripkin 2021-06-21 17:18 ` Guvenc Gulce 0 siblings, 1 reply; 4+ messages in thread From: Pavel Skripkin @ 2021-06-21 14:56 UTC (permalink / raw) To: syzbot Cc: coreteam, davem, dsahern, fw, kadlec, kgraul, kuba, linux-kernel, linux-s390, netdev, netfilter-devel, pablo, syzkaller-bugs, yoshfuji, guvenc On Sun, 20 Jun 2021 16:22:16 -0700 syzbot <syzbot+5dda108b672b54141857@syzkaller.appspotmail.com> wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 0c337952 Merge tag 'wireless-drivers-next-2021-06-16' > of g.. git tree: net-next > console output: > https://syzkaller.appspot.com/x/log.txt?x=1621de10300000 kernel > config: https://syzkaller.appspot.com/x/.config?x=a6380da8984033f1 > dashboard link: > https://syzkaller.appspot.com/bug?extid=5dda108b672b54141857 syz > repro: > https://syzkaller.appspot.com/x/repro.syz?x=121d2d20300000 C > reproducer: https://syzkaller.appspot.com/x/repro.c?x=100bd768300000 > > The issue was bisected to: > > commit f9006acc8dfe59e25aa75729728ac57a8d84fc32 > Author: Florian Westphal <fw@strlen.de> > Date: Wed Apr 21 07:51:08 2021 +0000 > > netfilter: arp_tables: pass table pointer via nf_hook_ops > I think, bisection is wrong this time :) It should be e0e4b8fa533858532f1b9ea9c6a4660d09beb37a ("net/smc: Add SMC statistics support") Some debug results: syzkaller repro just opens the socket and calls sendmsg. Ftrace log: 0) | smc_create() { 0) | smc_sock_alloc() { 0) + 88.493 us | smc_hash_sk(); 0) ! 131.487 us | } 0) ! 189.912 us | } 0) | smc_sendmsg() { 0) 2.808 us | smc_tx_sendmsg(); 0) ! 148.484 us | } That means, that smc_buf_create() wasn't called at all, so we need to check sndbuf_desc before dereferencing Something like this should work diff --git a/net/smc/smc_tx.c b/net/smc/smc_tx.c index 075c4f4b4..e24071b12 100644 --- a/net/smc/smc_tx.c +++ b/net/smc/smc_tx.c @@ -154,7 +154,7 @@ int smc_tx_sendmsg(struct smc_sock *smc, struct msghdr *msg, size_t len) goto out_err; } - if (len > conn->sndbuf_desc->len) + if (conn->sndbuf_desc && len > conn->sndbuf_desc->len) SMC_STAT_RMB_TX_SIZE_SMALL(smc, !conn->lnk); if (len > conn->peer_rmbe_size) Thoughts? +CC Guvenc Gulce With regards, Pavel Skripkin ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [syzbot] general protection fault in smc_tx_sendmsg 2021-06-21 14:56 ` Pavel Skripkin @ 2021-06-21 17:18 ` Guvenc Gulce 2021-06-21 19:04 ` Pavel Skripkin 0 siblings, 1 reply; 4+ messages in thread From: Guvenc Gulce @ 2021-06-21 17:18 UTC (permalink / raw) To: Pavel Skripkin, syzbot Cc: coreteam, davem, dsahern, fw, kadlec, kgraul, kuba, linux-kernel, linux-s390, netdev, netfilter-devel, pablo, syzkaller-bugs, yoshfuji On 21/06/2021 16:56, Pavel Skripkin wrote: > On Sun, 20 Jun 2021 16:22:16 -0700 > syzbot <syzbot+5dda108b672b54141857@syzkaller.appspotmail.com> wrote: > >> Hello, >> >> syzbot found the following issue on: >> >> HEAD commit: 0c337952 Merge tag 'wireless-drivers-next-2021-06-16' >> of g.. git tree: net-next >> console output: >> https://syzkaller.appspot.com/x/log.txt?x=1621de10300000 kernel >> config: https://syzkaller.appspot.com/x/.config?x=a6380da8984033f1 >> dashboard link: >> https://syzkaller.appspot.com/bug?extid=5dda108b672b54141857 syz >> repro: >> https://syzkaller.appspot.com/x/repro.syz?x=121d2d20300000 C >> reproducer: https://syzkaller.appspot.com/x/repro.c?x=100bd768300000 >> >> The issue was bisected to: >> >> commit f9006acc8dfe59e25aa75729728ac57a8d84fc32 >> Author: Florian Westphal <fw@strlen.de> >> Date: Wed Apr 21 07:51:08 2021 +0000 >> >> netfilter: arp_tables: pass table pointer via nf_hook_ops >> > I think, bisection is wrong this time :) > > It should be e0e4b8fa533858532f1b9ea9c6a4660d09beb37a ("net/smc: Add SMC > statistics support") > > > Some debug results: > > syzkaller repro just opens the socket and calls sendmsg. Ftrace log: > > > 0) | smc_create() { > 0) | smc_sock_alloc() { > 0) + 88.493 us | smc_hash_sk(); > 0) ! 131.487 us | } > 0) ! 189.912 us | } > 0) | smc_sendmsg() { > 0) 2.808 us | smc_tx_sendmsg(); > 0) ! 148.484 us | } > > > That means, that smc_buf_create() wasn't called at all, so we need to > check sndbuf_desc before dereferencing > > Something like this should work > > diff --git a/net/smc/smc_tx.c b/net/smc/smc_tx.c > index 075c4f4b4..e24071b12 100644 > --- a/net/smc/smc_tx.c > +++ b/net/smc/smc_tx.c > @@ -154,7 +154,7 @@ int smc_tx_sendmsg(struct smc_sock *smc, struct msghdr *msg, size_t len) > goto out_err; > } > > - if (len > conn->sndbuf_desc->len) > + if (conn->sndbuf_desc && len > conn->sndbuf_desc->len) > SMC_STAT_RMB_TX_SIZE_SMALL(smc, !conn->lnk); > > if (len > conn->peer_rmbe_size) > > > Thoughts? > > > +CC Guvenc Gulce > > > With regards, > Pavel Skripkin Thanks for analyzing the cause. Your approach would work but I would prefer that we check the state of the socket before doing the statistics relevant if check. This will ensure that smc_buf_create() was already called. I am testing the fix at the moment which would look like the following: diff --git a/net/smc/smc_tx.c b/net/smc/smc_tx.c index 075c4f4b41cf..289025cd545a 100644 --- a/net/smc/smc_tx.c +++ b/net/smc/smc_tx.c @@ -154,6 +154,9 @@ int smc_tx_sendmsg(struct smc_sock *smc, struct msghdr *msg, size_t len) goto out_err; } + if (sk->sk_state == SMC_INIT) + return -ENOTCONN; + if (len > conn->sndbuf_desc->len) SMC_STAT_RMB_TX_SIZE_SMALL(smc, !conn->lnk); ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [syzbot] general protection fault in smc_tx_sendmsg 2021-06-21 17:18 ` Guvenc Gulce @ 2021-06-21 19:04 ` Pavel Skripkin 0 siblings, 0 replies; 4+ messages in thread From: Pavel Skripkin @ 2021-06-21 19:04 UTC (permalink / raw) To: Guvenc Gulce Cc: syzbot, coreteam, davem, dsahern, fw, kadlec, kgraul, kuba, linux-kernel, linux-s390, netdev, netfilter-devel, pablo, syzkaller-bugs, yoshfuji On Mon, 21 Jun 2021 19:18:56 +0200 Guvenc Gulce <guvenc@linux.ibm.com> wrote: > > > On 21/06/2021 16:56, Pavel Skripkin wrote: > > On Sun, 20 Jun 2021 16:22:16 -0700 > > syzbot <syzbot+5dda108b672b54141857@syzkaller.appspotmail.com> > > wrote: > > > >> Hello, > >> > >> syzbot found the following issue on: > >> > >> HEAD commit: 0c337952 Merge tag > >> 'wireless-drivers-next-2021-06-16' of g.. git tree: net-next > >> console output: > >> https://syzkaller.appspot.com/x/log.txt?x=1621de10300000 kernel > >> config: https://syzkaller.appspot.com/x/.config?x=a6380da8984033f1 > >> dashboard link: > >> https://syzkaller.appspot.com/bug?extid=5dda108b672b54141857 syz > >> repro: > >> https://syzkaller.appspot.com/x/repro.syz?x=121d2d20300000 C > >> reproducer: > >> https://syzkaller.appspot.com/x/repro.c?x=100bd768300000 > >> > >> The issue was bisected to: > >> > >> commit f9006acc8dfe59e25aa75729728ac57a8d84fc32 > >> Author: Florian Westphal <fw@strlen.de> > >> Date: Wed Apr 21 07:51:08 2021 +0000 > >> > >> netfilter: arp_tables: pass table pointer via nf_hook_ops > >> > > I think, bisection is wrong this time :) > > > > It should be e0e4b8fa533858532f1b9ea9c6a4660d09beb37a ("net/smc: > > Add SMC statistics support") > > > > > > Some debug results: > > > > syzkaller repro just opens the socket and calls sendmsg. Ftrace log: > > > > > > 0) | smc_create() { > > 0) | smc_sock_alloc() { > > 0) + 88.493 us | smc_hash_sk(); > > 0) ! 131.487 us | } > > 0) ! 189.912 us | } > > 0) | smc_sendmsg() { > > 0) 2.808 us | smc_tx_sendmsg(); > > 0) ! 148.484 us | } > > > > > > That means, that smc_buf_create() wasn't called at all, so we need > > to check sndbuf_desc before dereferencing > > > > Something like this should work > > > > diff --git a/net/smc/smc_tx.c b/net/smc/smc_tx.c > > index 075c4f4b4..e24071b12 100644 > > --- a/net/smc/smc_tx.c > > +++ b/net/smc/smc_tx.c > > @@ -154,7 +154,7 @@ int smc_tx_sendmsg(struct smc_sock *smc, struct > > msghdr *msg, size_t len) goto out_err; > > } > > > > - if (len > conn->sndbuf_desc->len) > > + if (conn->sndbuf_desc && len > conn->sndbuf_desc->len) > > SMC_STAT_RMB_TX_SIZE_SMALL(smc, !conn->lnk); > > > > if (len > conn->peer_rmbe_size) > > > > > > Thoughts? > > > > > > +CC Guvenc Gulce > > > > > > With regards, > > Pavel Skripkin > > Thanks for analyzing the cause. Your approach would work but I would > prefer that we check the state of the socket before doing the > statistics relevant if check. This will ensure that smc_buf_create() > was already called. I am testing the fix at the moment which would > look like the following: > This sounds better. I knew, that my approach will just "silence" the bug, that's why I CCed you for better approach :) > diff --git a/net/smc/smc_tx.c b/net/smc/smc_tx.c > index 075c4f4b41cf..289025cd545a 100644 > --- a/net/smc/smc_tx.c > +++ b/net/smc/smc_tx.c > @@ -154,6 +154,9 @@ int smc_tx_sendmsg(struct smc_sock *smc, struct > msghdr *msg, size_t len) goto out_err; > } > > + if (sk->sk_state == SMC_INIT) > + return -ENOTCONN; > + > if (len > conn->sndbuf_desc->len) > SMC_STAT_RMB_TX_SIZE_SMALL(smc, !conn->lnk); > > With regards, Pavel Skripkin ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-06-21 19:05 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-06-20 23:22 [syzbot] general protection fault in smc_tx_sendmsg syzbot 2021-06-21 14:56 ` Pavel Skripkin 2021-06-21 17:18 ` Guvenc Gulce 2021-06-21 19:04 ` Pavel Skripkin
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