------------[ cut here ]------------ WARNING: CPU: 0 PID: 6934 at fs/buffer.c:1183 mark_buffer_dirty+0x284/0x490 fs/buffer.c:1183 Modules linked in: CPU: 0 UID: 0 PID: 6934 Comm: syz.4.62 Not tainted syzkaller #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025 pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--) pc : mark_buffer_dirty+0x284/0x490 fs/buffer.c:1183 lr : mark_buffer_dirty+0x284/0x490 fs/buffer.c:1183 sp : ffff8000a0b161b0 x29: ffff8000a0b161b0 x28: ffff0000d81f8158 x27: dfff800000000000 x26: ffff0000f720ec00 x25: ffff0000f46b4008 x24: ffff0000ddd5e2b8 x23: ffff0000d81f8018 x22: ffff0000ddd5d828 x21: 1fffe0001b03f02b x20: 0000000000000010 x19: ffff0000ddd5e2b8 x18: 00000000ffffffff x17: ffff0001fea8c870 x16: ffff80008052bd88 x15: 0000000000000001 x14: 1fffe0001bbabc57 x13: 0000000000000000 x12: 0000000000000000 x11: ffff60001bbabc58 x10: 0000000000ff0100 x9 : 0000000000000000 x8 : ffff0000d7bb8000 x7 : 0000000000000000 x6 : 0000000000000000 x5 : ffff0000f720ee00 x4 : ffff0000f720c400 x3 : ffff800080e79c94 x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000 Call trace: mark_buffer_dirty+0x284/0x490 fs/buffer.c:1183 (P) bfs_move_block fs/bfs/file.c:44 [inline] bfs_move_blocks fs/bfs/file.c:57 [inline] bfs_get_block+0x4d8/0x9d4 fs/bfs/file.c:126 __block_write_begin_int+0x53c/0x15e8 fs/buffer.c:2145 block_write_begin+0xa0/0x128 fs/buffer.c:2256 bfs_write_begin+0x48/0xec fs/bfs/file.c:180 generic_perform_write+0x244/0x7bc mm/filemap.c:4254 __generic_file_write_iter+0xfc/0x204 mm/filemap.c:4371 generic_file_write_iter+0x10c/0x47c mm/filemap.c:4397 __kernel_write_iter+0x310/0x738 fs/read_write.c:619 __kernel_write+0xe0/0x130 fs/read_write.c:639 __dump_emit fs/coredump.c:1220 [inline] dump_emit+0x220/0x31c fs/coredump.c:1258 writenote+0x178/0x28c fs/binfmt_elf.c:1434 write_note_info fs/binfmt_elf.c:1931 [inline] elf_core_dump+0x25dc/0x2fbc fs/binfmt_elf.c:2098 coredump_write+0x1084/0x1900 fs/coredump.c:1049 vfs_coredump+0x182c/0x2354 fs/coredump.c:1170 get_signal+0xe38/0x12f8 kernel/signal.c:3019 arch_do_signal_or_restart+0x1c0/0x4414 arch/arm64/kernel/signal.c:1619 exit_to_user_mode_loop+0x7c/0x178 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] arm64_exit_to_user_mode arch/arm64/kernel/entry-common.c:81 [inline] el0_da+0x174/0x230 arch/arm64/kernel/entry-common.c:541 el0t_64_sync_handler+0x90/0x12c arch/arm64/kernel/entry-common.c:746 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 irq event stamp: 544 hardirqs last enabled at (543): [] bh_lru_install fs/buffer.c:1353 [inline] hardirqs last enabled at (543): [] find_get_block_common+0x970/0xde8 fs/buffer.c:1410 hardirqs last disabled at (544): [] el1_brk64+0x20/0x54 arch/arm64/kernel/entry-common.c:412 softirqs last enabled at (224): [] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32 softirqs last disabled at (222): [] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19 ---[ end trace 0000000000000000 ]--- Unable to handle kernel paging request at virtual address dfff800000000005 KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f] Mem abort info: ESR = 0x0000000096000005 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x05: level 1 translation fault Data abort info: ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000 CM = 0, WnR = 0, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [dfff800000000005] address between user and kernel address ranges Internal error: Oops: 0000000096000005 [#1] SMP Modules linked in: CPU: 1 UID: 0 PID: 6934 Comm: syz.4.62 Tainted: G W syzkaller #0 PREEMPT Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025 pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--) pc : bfs_move_block fs/bfs/file.c:43 [inline] pc : bfs_move_blocks fs/bfs/file.c:57 [inline] pc : bfs_get_block+0x498/0x9d4 fs/bfs/file.c:126 lr : __getblk include/linux/buffer_head.h:380 [inline] lr : sb_getblk include/linux/buffer_head.h:386 [inline] lr : bfs_move_block fs/bfs/file.c:42 [inline] lr : bfs_move_blocks fs/bfs/file.c:57 [inline] lr : bfs_get_block+0x470/0x9d4 fs/bfs/file.c:126 sp : ffff8000a0b161f0 x29: ffff8000a0b16260 x28: ffff0000d81f8158 x27: dfff800000000000 x26: 0000000000000028 x25: ffff0000f46b4008 x24: 0000000000000000 x23: ffff0000d81f8018 x22: ffff0000ddd5f9f8 x21: 1fffe0001b03f02b x20: 0000000000000200 x19: 0000000000000016 x18: 1fffe000337db690 x17: ffff80008f59e000 x16: ffff800080538320 x15: 0000000000000001 x14: 1fffffbff870707e x13: 0000000000000000 x12: 0000000000000000 x11: ffff7fbff870707f x10: 0000000000ff0100 x9 : 0000000000000000 x8 : 0000000000000005 x7 : 0000000000000000 x6 : 0000000000000000 x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff800080e7cd14 x2 : 0000000000000001 x1 : 0000000000000040 x0 : 0000000000000000 Call trace: bfs_move_block fs/bfs/file.c:43 [inline] (P) bfs_move_blocks fs/bfs/file.c:57 [inline] (P) bfs_get_block+0x498/0x9d4 fs/bfs/file.c:126 (P) __block_write_begin_int+0x53c/0x15e8 fs/buffer.c:2145 block_write_begin+0xa0/0x128 fs/buffer.c:2256 bfs_write_begin+0x48/0xec fs/bfs/file.c:180 generic_perform_write+0x244/0x7bc mm/filemap.c:4254 __generic_file_write_iter+0xfc/0x204 mm/filemap.c:4371 generic_file_write_iter+0x10c/0x47c mm/filemap.c:4397 __kernel_write_iter+0x310/0x738 fs/read_write.c:619 __kernel_write+0xe0/0x130 fs/read_write.c:639 __dump_emit fs/coredump.c:1220 [inline] dump_emit+0x220/0x31c fs/coredump.c:1258 writenote+0x178/0x28c fs/binfmt_elf.c:1434 write_note_info fs/binfmt_elf.c:1938 [inline] elf_core_dump+0x2644/0x2fbc fs/binfmt_elf.c:2098 coredump_write+0x1084/0x1900 fs/coredump.c:1049 vfs_coredump+0x182c/0x2354 fs/coredump.c:1170 get_signal+0xe38/0x12f8 kernel/signal.c:3019 arch_do_signal_or_restart+0x1c0/0x4414 arch/arm64/kernel/signal.c:1619 exit_to_user_mode_loop+0x7c/0x178 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] arm64_exit_to_user_mode arch/arm64/kernel/entry-common.c:81 [inline] el0_da+0x174/0x230 arch/arm64/kernel/entry-common.c:541 el0t_64_sync_handler+0x90/0x12c arch/arm64/kernel/entry-common.c:746 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 Code: 97e6aa17 9100a31a f94012d4 d343ff48 (387b6908) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: 97e6aa17 bl 0xffffffffff9aa85c 4: 9100a31a add x26, x24, #0x28 8: f94012d4 ldr x20, [x22, #32] c: d343ff48 lsr x8, x26, #3 * 10: 387b6908 ldrb w8, [x8, x27] <-- trapping instruction