kernel BUG in sock_write_iter

Status: upstream: reported C repro on 2026/09/13 18:43
Reported-by: syzbot+d76c58ea1cdc964051a9@syzkaller.appspotmail.com
First crash: 4d19h, last: 4d17h
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-6-12 kernel BUG in sock_write_iter -1 syz, C 1 8d14h 8d14h 0/1 premoderation: reported C repro on 2026/09/09 22:48
android-5-15 kernel BUG in sock_write_iter -1 syz, C 1 7h51m 7h51m 0/2 upstream: reported C repro on 2026/09/18 05:26

Sample crash report:
------------[ cut here ]------------
kernel BUG at net/socket.c:719!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 305 Comm: syz-executor287 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:sock_sendmsg_nosec net/socket.c:719 [inline]
RIP: 0010:__sock_sendmsg net/socket.c:728 [inline]
RIP: 0010:sock_write_iter+0x3e7/0x3f0 net/socket.c:1134
Code: cc fd e9 72 fe ff ff 44 89 e9 80 e1 07 80 c1 03 38 c1 0f 8c 0e fe ff ff 4c 89 ef e8 d3 55 cc fd e9 01 fe ff ff e8 b9 ca 86 fd <0f> 0b 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 b8 1e
RSP: 0018:ffffc90000e07b60 EFLAGS: 00010293
RAX: ffffffff83ea9ee7 RBX: 00000000fffffdef RCX: ffff8881100f0000
RDX: 0000000000000000 RSI: 00000000fffffdef RDI: 00000000fffffdef
RBP: ffffc90000e07c90 R08: ffffc90000e077c7 R09: 1ffff920001c0ef8
R10: dffffc0000000000 R11: fffff520001c0ef9 R12: dffffc0000000000
R13: ffff888116ff3c00 R14: ffffc90000e07ba0 R15: 1ffff920001c0f70
FS:  000055558ed0f3c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000463390 CR3: 000000012370b000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 call_write_iter include/linux/fs.h:2282 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x5ef/0xd00 fs/read_write.c:584
 ksys_write+0x14a/0x260 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __x64_sys_write+0x7b/0x90 fs/read_write.c:646
 x64_sys_call+0x27b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7efdd5eb3cb9
Code: c0 79 93 eb d5 48 8d 7c 1d 00 eb 99 0f 1f 44 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 d8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe7c87ca08 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000200000000000 RCX: 00007efdd5eb3cb9
RDX: 0000000000000001 RSI: 0000200000000000 RDI: 0000000000000003
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe7c87cb48
R13: 0000000000000002 R14: 00002000000000c0 R15: 0000000000000002
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:sock_sendmsg_nosec net/socket.c:719 [inline]
RIP: 0010:__sock_sendmsg net/socket.c:728 [inline]
RIP: 0010:sock_write_iter+0x3e7/0x3f0 net/socket.c:1134
Code: cc fd e9 72 fe ff ff 44 89 e9 80 e1 07 80 c1 03 38 c1 0f 8c 0e fe ff ff 4c 89 ef e8 d3 55 cc fd e9 01 fe ff ff e8 b9 ca 86 fd <0f> 0b 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 b8 1e
RSP: 0018:ffffc90000e07b60 EFLAGS: 00010293
RAX: ffffffff83ea9ee7 RBX: 00000000fffffdef RCX: ffff8881100f0000
RDX: 0000000000000000 RSI: 00000000fffffdef RDI: 00000000fffffdef
RBP: ffffc90000e07c90 R08: ffffc90000e077c7 R09: 1ffff920001c0ef8
R10: dffffc0000000000 R11: fffff520001c0ef9 R12: dffffc0000000000
R13: ffff888116ff3c00 R14: ffffc90000e07ba0 R15: 1ffff920001c0f70
FS:  000055558ed0f3c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000463390 CR3: 000000012370b000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/13 19:51 android14-6.1 6308d6d3f1b1 70a60e12 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-1 kernel BUG in sock_write_iter
2026/09/13 19:11 android14-6.1 6308d6d3f1b1 70a60e12 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-1 kernel BUG in sock_write_iter
2026/09/13 18:33 android14-6.1 6308d6d3f1b1 70a60e12 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-1 kernel BUG in sock_write_iter
2026/09/13 17:52 android14-6.1 6308d6d3f1b1 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 kernel BUG in sock_write_iter
* Struck through repros no longer work on HEAD.