syzbot


assert "ISSET(bp->b_flags, B_BC)" failed in vfs_bio.c (2)

Status: upstream: reported on 2025/11/24 19:49
Reported-by: syzbot+769b6dd090e5fdcccd48@syzkaller.appspotmail.com
First crash: 90d, last: 11d
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
openbsd assert "ISSET(bp->b_flags, B_BC)" failed in vfs_bio.c -1 8 591d 755d 0/3 auto-obsoleted due to no activity on 2024/10/09 15:35

Sample crash report:
panic: kernel diagnostic assertion "ISSET(bp->b_flags, B_BC)" failed: file "/syzkaller/managers/main/kernel/sys/kern/vfs_bio.c", line 1661
Starting stack trace...
panic(ffffffff83381a45) at panic+0x1ba sys/kern/subr_prf.c:229
__assert(ffffffff833bbfdb,ffffffff833be3ce,67d,ffffffff83421427) at __assert+0x29 sys/kern/subr_prf.c:-1
bufcache_take(fffffd806af07e70) at bufcache_take+0x2d3 sys/kern/vfs_bio.c:1662
getblk(fffffd806cb459a0,0,4000,0,ffffffffffffffff) at getblk+0x214 sys/kern/vfs_bio.c:1025
bread(fffffd806cb459a0,0,4000,ffff80002a8c50d0) at bread+0x45 bio_doread sys/kern/vfs_bio.c:418 [inline]
bread(fffffd806cb459a0,0,4000,ffff80002a8c50d0) at bread+0x45 sys/kern/vfs_bio.c:463
ffs_read(ffff80002a8c5140) at ffs_read+0x325 sys/ufs/ffs/ffs_vnops.c:-1
VOP_READ(fffffd806cb459a0,ffff80002a8c52e8,0,fffffd8007bfd478) at VOP_READ+0x101 sys/kern/vfs_vops.c:227
ufs_readdir(ffff80002a8c53a0) at ufs_readdir+0x16d sys/ufs/ufs/ufs_vnops.c:1366
VOP_READDIR(fffffd806cb459a0,ffff80002a8c5428,fffffd8007bfd478,ffff80002a8c546c) at VOP_READDIR+0x125 sys/kern/vfs_vops.c:453
sys_getdents(ffff80002a776538,ffff80002a8c55b0,ffff80002a8c5500) at sys_getdents+0x2dd sys/kern/vfs_syscalls.c:3183
syscall(ffff80002a8c55b0) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80002a8c55b0) at syscall+0x962 sys/arch/amd64/amd64/trap.c:775
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x72e67b1d6590, count: 245
End of stack trace.

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/11 13:02 openbsd 960213463517 018ebef2 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main assert "ISSET(bp->b_flags, B_BC)" failed in vfs_bio.c
2025/11/24 19:48 openbsd 879ea5f6fdb7 bf6fe8fe .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-multicore assert "ISSET(bp->b_flags, B_BC)" failed in vfs_bio.c
* Struck through repros no longer work on HEAD.