WARNING in kcov_mmap

Status: upstream: reported on 2026/07/28 21:50
Reported-by: syzbot+06444c2bc49932ab195a@syzkaller.appspotmail.com
First crash: 17d, last: 10d
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in kcov_mmap mm -1 14 1545d 1599d 22/29 fixed on 2023/02/24 13:50

Sample crash report:
------------[ cut here ]------------
vm_insert_page() failed
WARNING: CPU: 0 PID: 4470 at kernel/kcov.c:492 kcov_mmap+0x10a/0x120 kernel/kcov.c:492
Modules linked in:
CPU: 0 PID: 4470 Comm: syz.4.49 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:kcov_mmap+0x10a/0x120 kernel/kcov.c:492
Code: 89 df 48 89 c2 e8 56 7a 34 00 85 c0 74 d0 80 3d f9 3d fe 0b 00 75 c7 c6 05 f0 3d fe 0b 01 48 c7 c7 b3 02 c8 8b e8 e6 13 3c 08 <0f> 0b eb b0 31 ed e9 7b ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 90
RSP: 0018:ffffc9000322fb50 EFLAGS: 00010246
RAX: 3223f2a20c697700 RBX: ffff8880203ec318 RCX: ffff88802a5b9dc0
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff8880b902795b R09: 1ffff11017204f2b
R10: dffffc0000000000 R11: ffffed1017204f2c R12: ffff888020307a00
R13: 0000000000400000 R14: 0000000000040000 R15: ffff888020307a08
FS:  000055557daf9500(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa252002028 CR3: 000000005913b000 CR4: 00000000003506e0
DR0: 0000000000010000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 call_mmap include/linux/fs.h:2178 [inline]
 mmap_file+0x5d/0xb0 mm/util.c:1092
 __mmap_region mm/mmap.c:1796 [inline]
 mmap_region+0x1048/0x1730 mm/mmap.c:2933
 do_mmap+0x801/0xe30 mm/mmap.c:1586
 vm_mmap_pgoff+0x1c1/0x2d0 mm/util.c:551
 ksys_mmap_pgoff+0x4e2/0x790 mm/mmap.c:1635
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fa253dcad82
Code: 4f 01 00 0f 1f 44 00 00 41 f7 c1 ff 0f 00 00 75 27 55 89 cd 53 48 89 fb 48 85 ff 74 3b 41 89 ea 48 89 df b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 6e 5b 5d c3 0f 1f 00 48 c7 c0 e8 ff ff ff 64
RSP: 002b:00007ffc353a8288 EFLAGS: 00000206 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007fa251bc0000 RCX: 00007fa253dcad82
RDX: 0000000000000003 RSI: 0000000000400000 RDI: 00007fa251bc0000
RBP: 0000000000000011 R08: 00000000000000db R09: 0000000000000000
R10: 0000000000000011 R11: 0000000000000206 R12: 0000000000000003
R13: 0000000000000003 R14: 0000000000000000 R15: 00007fa254052fa0
 </TASK>

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/05 08:25 linux-5.15.y 6e2fd6534337 52aa2820 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in kcov_mmap
2026/07/29 07:35 linux-5.15.y 674f684f7c61 19622d9d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in kcov_mmap
2026/07/29 07:23 linux-5.15.y 674f684f7c61 19622d9d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in kcov_mmap
2026/07/28 21:50 linux-5.15.y 674f684f7c61 edc8a875 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in kcov_mmap
* Struck through repros no longer work on HEAD.