Dear Maintainers， When using our customized Syzkaller to fuzz the latest Linux kernel, the following crash (37th and 76th)was triggered. 37th： HEAD commit: 6537cfb395f352782918d8ee7b7f10ba2cc3cbf2 git tree: upstream Output:https://github.com/pghk13/Kernel-Bug/blob/main/1220_6.13rc_KASAN/2.%E5%9B%9E%E5%BD%92-11/14-KASAN_%20slab-out-of-bounds%20Read%20in%20hfsplus_bnode_read/14call_trace.txt Kernel config:https://github.com/pghk13/Kernel-Bug/blob/main/0305_6.15rc1/config.txt C reproducer:https://github.com/pghk13/Kernel-Bug/blob/main/0219_6.13rc7_todo/76-UBSAN_%20shift-out-of-bounds%20in%20bch2_trans_iter_init_outlined/37repro.c Syzlang reproducer: https://github.com/pghk13/Kernel-Bug/blob/main/0219_6.13rc7_todo/76-UBSAN_%20shift-out-of-bounds%20in%20bch2_trans_iter_init_outlined/37repro.txt 76th： HEAD commit: 6537cfb395f352782918d8ee7b7f10ba2cc3cbf2 git tree: upstream Output:https://github.com/pghk13/Kernel-Bug/blob/main/0219_6.13rc7_todo/76-UBSAN_%20shift-out-of-bounds%20in%20bch2_trans_iter_init_outlined/76call_trace.txt Kernel config:https://github.com/pghk13/Kernel-Bug/blob/main/0305_6.15rc1/config.txt C reproducer:https://github.com/pghk13/Kernel-Bug/blob/main/0219_6.13rc7_todo/76-UBSAN_%20shift-out-of-bounds%20in%20bch2_trans_iter_init_outlined/76repro.c Syzlang reproducer: https://github.com/pghk13/Kernel-Bug/blob/main/0219_6.13rc7_todo/76-UBSAN_%20shift-out-of-bounds%20in%20bch2_trans_iter_init_outlined/76repro.txt The two errors seem to have the same error points, but there are a few differences in the process. They all trigger warnings in the __folio_mark_dirty+0xb50/0xf10 function of backing-dev.h:251. In __folio_mark_dirty function, a warning is triggered when the code tries to access or modify the backing-dev information. The 76th call stack has longer call chains from file writebacks: writeback work queues → writeback inodes → GFS2 write inodes → log refreshes. We have reproduced this issue several times on 6.15-rc1 again. If you fix this issue, please add the following tag to the commit: Reported-by: Kun Hu <huk23@xxxxxxxxxxxxxx>, Jiaji Qin <jjtan24@xxxxxxxxxxxxxx>, Shuoran Bai <baishuoran@xxxxxxxxxxxx> 37th： ================================================================== WARNING: CPU: 2 PID: 9494 at ./include/linux/backing-dev.h:251 __folio_mark_dirty+0xb50/0xf10 Modules linked in: CPU: 2 UID: 0 PID: 9494 Comm: gfs2_logd/syz:s Not tainted 6.15.0-rc1 #1 PREEMPT(full) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 RIP: 0010:__folio_mark_dirty+0xb50/0xf10 Code: ff ff 48 8d 78 70 e8 af e3 76 09 31 ff 89 c6 89 44 24 08 e8 72 d3 c5 ff 8b 44 24 08 85 c0 0f 85 af f9 ff ff e8 51 d1 c5 ff 90 <0f> 0b 90 e9 a1 f9 ff ff e8 43 d1 c5 ff 90 0f 0b 90 e9 59 f5 ff ff RSP: 0018:ffffc90014bb7b18 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ffff88804298cb58 RCX: ffffffff81f5408e RDX: 0000000000000000 RSI: ffff888023edc900 RDI: 0000000000000002 RBP: ffffea00015c9d80 R08: 0000000000000000 R09: ffffed10085319a0 R10: ffffed100853199f R11: ffff88804298ccff R12: 0000000000000246 R13: ffff888049bd8bc8 R14: 0000000000000001 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888097c6b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff2c7be9028 CR3: 000000000e180000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: <TASK> mark_buffer_dirty+0x358/0x410 gfs2_unpin+0x106/0xef0 buf_lo_after_commit+0x155/0x230 gfs2_log_flush+0xd95/0x2cb0 gfs2_logd+0x29b/0x12c0 kthread+0x447/0x8a0 ret_from_fork+0x48/0x80 ret_from_fork_asm+0x1a/0x30 </TASK> extracting prog: 1h56m11.644263162s minimizing prog: 14m12.695891417s simplifying prog options: 0s extracting C: 32.234365976s simplifying C: 9m50.565845853s 76th： ================================================================== WARNING: CPU: 3 PID: 3051 at ./include/linux/backing-dev.h:251 __folio_mark_dirty+0xb50/0xf10 Modules linked in: CPU: 3 UID: 0 PID: 3051 Comm: kworker/u18:5 Not tainted 6.15.0-rc1 #1 PREEMPT(full) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Workqueue: writeback wb_workfn (flush-7:0) RIP: 0010:__folio_mark_dirty+0xb50/0xf10 Code: ff ff 48 8d 78 70 e8 af e3 76 09 31 ff 89 c6 89 44 24 08 e8 72 d3 c5 ff 8b 44 24 08 85 c0 0f 85 af f9 ff ff e8 51 d1 c5 ff 90 <0f> 0b 90 e9 a1 f9 ff ff e8 43 d1 c5 ff 90 0f 0b 90 e9 59 f5 ff ff RSP: 0018:ffffc90011e2f410 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ffff88804266bfd8 RCX: ffffffff81f5408e RDX: 0000000000000000 RSI: ffff888043e48000 RDI: 0000000000000002 RBP: ffffea000086e9c0 R08: 0000000000000000 R09: ffffed10084cd830 R10: ffffed10084cd82f R11: ffff88804266c17f R12: 0000000000000246 R13: ffff888012bf87f0 R14: 0000000000000001 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880eb46b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6410e8e140 CR3: 0000000023648000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: <TASK> mark_buffer_dirty+0x358/0x410 gfs2_unpin+0x106/0xef0 buf_lo_after_commit+0x155/0x230 gfs2_log_flush+0xd95/0x2cb0 gfs2_write_inode+0x371/0x450 __writeback_single_inode+0xad7/0xf50 writeback_sb_inodes+0x5f5/0xee0 __writeback_inodes_wb+0xbe/0x270 wb_writeback+0x728/0xb50 wb_workfn+0x96e/0xe90 process_scheduled_works+0x5de/0x1bd0 worker_thread+0x5a9/0xd10 kthread+0x447/0x8a0 ret_from_fork+0x48/0x80 ret_from_fork_asm+0x1a/0x30 </TASK> thanks, Kun Hu
