From: syzbot <syzbot+d5c77cabf7a3492aa650@syzkaller.appspotmail.com>
To: linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org,
netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com
Subject: [syzbot] [nfs?] [net?] KASAN: vmalloc-out-of-bounds Read in rpc_queue_upcall
Date: Mon, 07 Sep 2026 10:44:39 -0700 [thread overview]
Message-ID: <6a9ef807.2bb5a69c.24b23c.0007.GAE@google.com> (raw)
Hello,
syzbot found the following issue on:
HEAD commit: df2908090cda Linux 7.3-rc2
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=1416cc8e580000
kernel config: https://syzkaller.appspot.com/x/.config?x=8c5c3949d762a91f
dashboard link: https://syzkaller.appspot.com/bug?extid=d5c77cabf7a3492aa650
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14daa071580000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d5c77cabf7a3492aa650@syzkaller.appspotmail.com
vmalloc memory
list_add corruption. prev->next should be next (ffff8880358a6c00), but was 0000000000000000. (prev=ffffc90003cbfa10).
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:32!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 2 UID: 0 PID: 5997 Comm: syz-executor965 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:__list_add_valid_or_report+0xfb/0x130 lib/list_debug.c:32
Code: b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 75 3d 49 8b 55 00 4c 89 e9 48 89 de 48 c7 c7 c0 12 62 8c e8 d6 35 ee fb 90 <0f> 0b 4c 89 e7 e8 bb 38 4b fd e9 3a ff ff ff 4c 89 ef e8 ae 38 4b
RSP: 0018:ffffc90003cbf938 EFLAGS: 00010282
RAX: 0000000000000075 RBX: ffff8880358a6c00 RCX: 0000000000000000
RDX: 0000000000000075 RSI: ffffffff81ea06f9 RDI: fffff52000797f18
RBP: ffffc90003cbfa10 R08: 0000000000000007 R09: 0000000000000000
R10: 8000000000000001 R11: 0000000000000001 R12: ffff8880358a6c08
R13: ffffc90003cbfa10 R14: ffff8880358a6c08 R15: ffffc90003cbfa10
FS: 00007f6eeac506c0(0000) GS:ffff8880d5d5d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbbfc3d4000 CR3: 0000000026a53000 CR4: 0000000000352ef0
Call Trace:
<TASK>
__list_add_valid include/linux/list.h:104 [inline]
__list_add include/linux/list.h:169 [inline]
list_add_tail include/linux/list.h:206 [inline]
rpc_queue_upcall+0x2ff/0x530 net/sunrpc/rpc_pipe.c:142
__cld_pipe_upcall fs/nfsd/nfs4recover.c:668 [inline]
cld_pipe_upcall fs/nfsd/nfs4recover.c:691 [inline]
nfsd4_cld_grace_start fs/nfsd/nfs4recover.c:1305 [inline]
nfsd4_cld_tracking_init+0x85a/0x10f0 fs/nfsd/nfs4recover.c:1494
nfsd4_client_tracking_init+0xe5/0x1c0 fs/nfsd/nfs4recover.c:1941
nfs4_state_start_net.cold+0xb7/0x480 fs/nfsd/nfs4state.c:9838
nfsd_startup_net fs/nfsd/nfssvc.c:391 [inline]
nfsd_svc+0x54a/0x7d0 fs/nfsd/nfssvc.c:775
write_threads+0x316/0x600 fs/nfsd/nfsctl.c:438
nfsctl_transaction_write+0x106/0x1a0 fs/nfsd/nfsctl.c:114
vfs_write+0x2aa/0x1050 fs/read_write.c:685
ksys_write+0x12a/0x250 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6eeaca601e
Code: 08 0f 85 f5 e2 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 90 41 57 41 56 4d 89 c6 41 55 4d 89 cd 41 54 55 53 48 83 ec 08
RSP: 002b:00007f6eeac501a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f6eeac506c0 RCX: 00007f6eeaca601e
RDX: 0000000000000002 RSI: 00007f6eeacf10e4 RDI: 0000000000000003
RBP: 0000000000000021 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffd0
R13: 0000000000000000 R14: 00007ffe260d9b80 R15: 00007ffe260d9c68
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__list_add_valid_or_report+0xfb/0x130 lib/list_debug.c:32
Code: b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 75 3d 49 8b 55 00 4c 89 e9 48 89 de 48 c7 c7 c0 12 62 8c e8 d6 35 ee fb 90 <0f> 0b 4c 89 e7 e8 bb 38 4b fd e9 3a ff ff ff 4c 89 ef e8 ae 38 4b
RSP: 0018:ffffc90003cbf938 EFLAGS: 00010282
RAX: 0000000000000075 RBX: ffff8880358a6c00 RCX: 0000000000000000
RDX: 0000000000000075 RSI: ffffffff81ea06f9 RDI: fffff52000797f18
RBP: ffffc90003cbfa10 R08: 0000000000000007 R09: 0000000000000000
R10: 8000000000000001 R11: 0000000000000001 R12: ffff8880358a6c08
R13: ffffc90003cbfa10 R14: ffff8880358a6c08 R15: ffffc90003cbfa10
FS: 00007f6eeac506c0(0000) GS:ffff8880d5d5d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbbfc3d4000 CR3: 0000000026a53000 CR4: 0000000000352ef0
---
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.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
next reply other threads:[~2026-09-07 17:44 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-07 17:44 syzbot [this message]
2026-09-07 19:15 ` [syzbot] [nfs?] [net?] KASAN: vmalloc-out-of-bounds Read in rpc_queue_upcall Chuck Lever
2026-09-07 19:31 ` syzbot
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=6a9ef807.2bb5a69c.24b23c.0007.GAE@google.com \
--to=syzbot+d5c77cabf7a3492aa650@syzkaller.appspotmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-nfs@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=syzkaller-bugs@googlegroups.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.