Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 1 UID: 0 PID: 13937 Comm: kworker/u8:22 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: writeback wb_workfn (flush-8:0) RIP: 0010:bvec_set_page include/linux/bvec.h:44 [inline] RIP: 0010:__bio_add_page block/bio.c:992 [inline] RIP: 0010:bio_add_page+0x462/0x6e0 block/bio.c:1048 Code: fd 48 8b 1b 48 8b 44 24 30 42 0f b6 04 30 84 c0 0f 85 c3 01 00 00 48 8b 14 24 0f b7 02 c1 e0 04 48 01 c3 48 89 d8 48 c1 e8 03 <42> 80 3c 30 00 74 0c 48 89 df e8 ef c2 a5 fd 48 8b 14 24 48 8b 44 RSP: 0018:ffffc90003bfe840 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff8880758f3d00 RDX: ffff8880472592f8 RSI: 00000000ffffefff RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffea0001a6d6c7 R09: 1ffffd400034dad8 R10: dffffc0000000000 R11: fffff9400034dad9 R12: 1ffff11008e4b25f R13: 0000000000001000 R14: dffffc0000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125548000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fab5d9440a1 CR3: 000000003fd8a000 CR4: 00000000003526f0 Call Trace: bio_add_folio+0x64/0x90 block/bio.c:1084 io_submit_add_bh fs/ext4/page-io.c:465 [inline] ext4_bio_write_folio+0x1446/0x1ea0 fs/ext4/page-io.c:603 mpage_process_page_bufs+0x6d5/0x8e0 fs/ext4/inode.c:2194 mpage_prepare_extent_to_map+0xe1b/0x16f0 fs/ext4/inode.c:2733 ext4_do_writepages+0xbac/0x4670 fs/ext4/inode.c:2874 ext4_writepages+0x241/0x3b0 fs/ext4/inode.c:3022 do_writepages+0x32e/0x550 mm/page-writeback.c:2554 __writeback_single_inode+0x133/0x10e0 fs/fs-writeback.c:1750 writeback_sb_inodes+0x979/0x19d0 fs/fs-writeback.c:2042 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2118 wb_writeback+0x459/0xb00 fs/fs-writeback.c:2229 wb_check_start_all fs/fs-writeback.c:2355 [inline] wb_do_writeback fs/fs-writeback.c:2381 [inline] wb_workfn+0x921/0xf10 fs/fs-writeback.c:2414 process_one_work+0x9a3/0x1710 kernel/workqueue.c:3288 process_scheduled_works kernel/workqueue.c:3379 [inline] worker_thread+0xba8/0x11e0 kernel/workqueue.c:3465 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:bvec_set_page include/linux/bvec.h:44 [inline] RIP: 0010:__bio_add_page block/bio.c:992 [inline] RIP: 0010:bio_add_page+0x462/0x6e0 block/bio.c:1048 Code: fd 48 8b 1b 48 8b 44 24 30 42 0f b6 04 30 84 c0 0f 85 c3 01 00 00 48 8b 14 24 0f b7 02 c1 e0 04 48 01 c3 48 89 d8 48 c1 e8 03 <42> 80 3c 30 00 74 0c 48 89 df e8 ef c2 a5 fd 48 8b 14 24 48 8b 44 RSP: 0018:ffffc90003bfe840 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff8880758f3d00 RDX: ffff8880472592f8 RSI: 00000000ffffefff RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffea0001a6d6c7 R09: 1ffffd400034dad8 R10: dffffc0000000000 R11: fffff9400034dad9 R12: 1ffff11008e4b25f R13: 0000000000001000 R14: dffffc0000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125548000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbd501e7158 CR3: 000000007b33c000 CR4: 00000000003526f0 ---------------- Code disassembly (best guess): 0: fd std 1: 48 8b 1b mov (%rbx),%rbx 4: 48 8b 44 24 30 mov 0x30(%rsp),%rax 9: 42 0f b6 04 30 movzbl (%rax,%r14,1),%eax e: 84 c0 test %al,%al 10: 0f 85 c3 01 00 00 jne 0x1d9 16: 48 8b 14 24 mov (%rsp),%rdx 1a: 0f b7 02 movzwl (%rdx),%eax 1d: c1 e0 04 shl $0x4,%eax 20: 48 01 c3 add %rax,%rbx 23: 48 89 d8 mov %rbx,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 42 80 3c 30 00 cmpb $0x0,(%rax,%r14,1) <-- trapping instruction 2f: 74 0c je 0x3d 31: 48 89 df mov %rbx,%rdi 34: e8 ef c2 a5 fd call 0xfda5c328 39: 48 8b 14 24 mov (%rsp),%rdx 3d: 48 rex.W 3e: 8b .byte 0x8b 3f: 44 rex.R