Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 0 UID: 0 PID: 6157 Comm: syz.0.48 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:bio_get_first_bvec block/blk-merge.c:22 [inline] RIP: 0010:bio_get_last_bvec block/blk-merge.c:30 [inline] RIP: 0010:bio_seg_gap+0x1c6/0x7d0 block/blk-merge.c:743 Code: fd 48 ba 00 00 00 00 00 fc ff df 49 8b 06 48 89 5c 24 20 49 89 de 49 c1 e6 04 48 89 44 24 08 4a 8d 2c 30 48 89 e8 48 c1 e8 03 <80> 3c 10 00 74 12 48 89 ef e8 7c 04 b9 fd 48 ba 00 00 00 00 00 fc RSP: 0018:ffffc9000af9eb40 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff888025673d00 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffff888079928b70 RBP: 0000000000000000 R08: ffff8880255bc4d7 R09: 1ffff11004ab789a R10: dffffc0000000000 R11: ffffed1004ab789b R12: 0000000000000c00 R13: 0000000000000000 R14: 0000000000000000 R15: ffff888079928b40 FS: 0000000000000000(0000) GS:ffff888125ecc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555628b35c8 CR3: 0000000078570000 CR4: 00000000003526f0 Call Trace: bio_attempt_back_merge+0x4ae/0x930 block/blk-merge.c:940 blk_attempt_plug_merge+0x145/0x1d0 block/blk-merge.c:1073 blk_mq_attempt_bio_merge block/blk-mq.c:3022 [inline] blk_mq_submit_bio+0x1aad/0x26e0 block/blk-mq.c:3186 __submit_bio+0x207/0x5a0 block/blk-core.c:637 __submit_bio_noacct_mq block/blk-core.c:724 [inline] submit_bio_noacct_nocheck+0x2eb/0xa50 block/blk-core.c:755 submit_bio_wait+0x104/0x200 block/bio.c:1389 blkdev_issue_discard+0x113/0x1b0 block/blk-lib.c:95 ext4_mb_clear_bb fs/ext4/mballoc.c:6620 [inline] ext4_free_blocks+0xcc2/0x1c00 fs/ext4/mballoc.c:6770 ext4_clear_blocks+0x372/0x3f0 fs/ext4/indirect.c:888 ext4_free_data fs/ext4/indirect.c:962 [inline] ext4_ind_truncate+0x701/0xb30 fs/ext4/indirect.c:1154 ext4_truncate+0xb14/0x12f0 fs/ext4/inode.c:4620 ext4_evict_inode+0x85e/0xe80 fs/ext4/inode.c:260 evict+0x5f4/0xae0 fs/inode.c:837 __dentry_kill+0x209/0x660 fs/dcache.c:669 dput+0x19f/0x2b0 fs/dcache.c:911 __fput+0x68e/0xa70 fs/file_table.c:476 task_work_run+0x1d4/0x260 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6bd/0x2300 kernel/exit.c:970 do_group_exit+0x21c/0x2d0 kernel/exit.c:1111 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop kernel/entry/common.c:75 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline] irqentry_exit+0x171/0x640 kernel/entry/common.c:196 exc_page_fault+0xab/0x100 arch/x86/mm/fault.c:1535 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x367ad549795b Code: Unable to access opcode bytes at 0x367ad5497931. RSP: 002b:0000200000000088 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f27463e5fa0 RCX: 00007f274618f6c9 RDX: 00002000000000c0 RSI: 0000200000000080 RDI: 0000000004000200 RBP: 00007f2746211f91 R08: 0000200000000200 R09: 0000200000000200 R10: 0000200000000100 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f27463e6038 R14: 00007f27463e5fa0 R15: 00007fffaeb2baf8 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:bio_get_first_bvec block/blk-merge.c:22 [inline] RIP: 0010:bio_get_last_bvec block/blk-merge.c:30 [inline] RIP: 0010:bio_seg_gap+0x1c6/0x7d0 block/blk-merge.c:743 Code: fd 48 ba 00 00 00 00 00 fc ff df 49 8b 06 48 89 5c 24 20 49 89 de 49 c1 e6 04 48 89 44 24 08 4a 8d 2c 30 48 89 e8 48 c1 e8 03 <80> 3c 10 00 74 12 48 89 ef e8 7c 04 b9 fd 48 ba 00 00 00 00 00 fc RSP: 0018:ffffc9000af9eb40 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff888025673d00 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffff888079928b70 RBP: 0000000000000000 R08: ffff8880255bc4d7 R09: 1ffff11004ab789a R10: dffffc0000000000 R11: ffffed1004ab789b R12: 0000000000000c00 R13: 0000000000000000 R14: 0000000000000000 R15: ffff888079928b40 FS: 0000000000000000(0000) GS:ffff888125ecc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1eaafb3ad8 CR3: 000000007876a000 CR4: 00000000003526f0 ---------------- Code disassembly (best guess): 0: fd std 1: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx 8: fc ff df b: 49 8b 06 mov (%r14),%rax e: 48 89 5c 24 20 mov %rbx,0x20(%rsp) 13: 49 89 de mov %rbx,%r14 16: 49 c1 e6 04 shl $0x4,%r14 1a: 48 89 44 24 08 mov %rax,0x8(%rsp) 1f: 4a 8d 2c 30 lea (%rax,%r14,1),%rbp 23: 48 89 e8 mov %rbp,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 80 3c 10 00 cmpb $0x0,(%rax,%rdx,1) <-- trapping instruction 2e: 74 12 je 0x42 30: 48 89 ef mov %rbp,%rdi 33: e8 7c 04 b9 fd call 0xfdb904b4 38: 48 rex.W 39: ba 00 00 00 00 mov $0x0,%edx 3e: 00 fc add %bh,%ah