jfs_dirty_inode called on read-only volume Is remount racy? jfs_dirty_inode called on read-only volume Is remount racy? ================================================================== BUG: KASAN: null-ptr-deref in instrument_atomic_read include/linux/instrumented.h:71 [inline] BUG: KASAN: null-ptr-deref in test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline] BUG: KASAN: null-ptr-deref in txBeginAnon+0xa0/0x150 fs/jfs/jfs_txnmgr.c:465 Read of size 8 at addr 0000000000000040 by task syz.4.16/4448 CPU: 0 PID: 4448 Comm: syz.4.16 Not tainted 5.15.189-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 __kasan_report mm/kasan/report.c:438 [inline] kasan_report+0xd5/0x130 mm/kasan/report.c:451 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x27b/0x290 mm/kasan/generic.c:189 instrument_atomic_read include/linux/instrumented.h:71 [inline] test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline] txBeginAnon+0xa0/0x150 fs/jfs/jfs_txnmgr.c:465 extAlloc+0xf3/0xf30 fs/jfs/jfs_extent.c:81 jfs_get_block+0x343/0xab0 fs/jfs/inode.c:258 nobh_write_begin+0x3d5/0xe80 fs/buffer.c:2650 jfs_write_begin+0x3d/0x80 fs/jfs/inode.c:322 generic_perform_write+0x2aa/0x530 mm/filemap.c:3785 __generic_file_write_iter+0x25f/0x4e0 mm/filemap.c:3912 generic_file_write_iter+0xa6/0x1b0 mm/filemap.c:3944 call_write_iter include/linux/fs.h:2172 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x712/0xd00 fs/read_write.c:594 ksys_pwrite64 fs/read_write.c:701 [inline] __do_sys_pwrite64 fs/read_write.c:711 [inline] __se_sys_pwrite64 fs/read_write.c:708 [inline] __x64_sys_pwrite64+0x194/0x220 fs/read_write.c:708 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: 0033:0x7f9574fb79a9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f9572e1f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000012 RAX: ffffffffffffffda RBX: 00007f95751defa0 RCX: 00007f9574fb79a9 RDX: 0000000000000001 RSI: 0000200000000080 RDI: 0000000000000005 RBP: 00007f9575039d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000008080c61 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f95751defa0 R15: 00007ffd2052e518 ==================================================================