Created attachment 281483 [details] The (compressed) crafted image which causes crash - Overview After mounting crafted image, I got kernel panic because of null pointer dereference while running attached program. - Reproduce mkdir test mount -t btrfs 04.img test gcc 04.c cp a.out test cd test ./a.out - Messages [ 125.531334] btrfs bad mapping eb start 29761536 len 4096, wanted 1787708 2410692 [ 125.533687] BUG: unable to handle kernel NULL pointer dereference at 00000000000003e4 [ 125.535624] #PF error: [normal kernel read fault] [ 125.536836] PGD 800000022b892067 P4D 800000022b892067 PUD 22b891067 PMD 0 [ 125.538509] Oops: 0000 [#1] SMP PTI [ 125.539376] CPU: 0 PID: 627 Comm: in:imklog Tainted: G W 5.0.0-rc8+ #9 [ 125.541291] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 [ 125.543458] RIP: 0010:fsnotify+0x39a/0x3d0 [ 125.544468] Code: c7 80 65 15 8a 89 45 a8 e8 23 3d e3 ff 8b 45 a8 e9 3e ff ff ff 31 c0 eb e2 48 8b 02 48 8b 58 08 4c 8d 60 e0 8b 80 f8 00 00 00 <0b> 83 e4 03 00 00 e9 d3 fc ff ff 45 31 ff e9 42 fd ff ff 31 c0 e9 [ 125.549012] RSP: 0018:ffffa8360108fe10 EFLAGS: 00010246 [ 125.550283] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000001 [ 125.552004] RDX: ffff9066f3543610 RSI: 0000000000000001 RDI: 0000000000000000 [ 125.553737] RBP: ffffa8360108fe98 R08: 0000000000000000 R09: 0000000000000000 [ 125.555462] R10: ffffc90108bb1a80 R11: ffff9066f7401500 R12: ffff9066ebb4e000 [ 125.557201] R13: 0000000000000001 R14: ffff9066f25102d0 R15: ffff9066f3543610 [ 125.558929] FS: 00007f5ab210c700(0000) GS:ffff9066f7a00000(0000) knlGS:0000000000000000 [ 125.562877] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 125.564292] CR2: 00000000000003e4 CR3: 000000022beee006 CR4: 00000000000206f0 [ 125.566052] Call Trace: [ 125.566674] vfs_read+0x127/0x140 [ 125.567501] ksys_read+0x55/0xc0 [ 125.568305] __x64_sys_read+0x1a/0x20 [ 125.569231] do_syscall_64+0x5a/0x110 [ 125.570147] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 125.571393] RIP: 0033:0x7f5ab455b51d [ 125.572286] Code: be 20 00 00 75 10 b8 00 00 00 00 0f 05 48 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 4e fc ff ff 48 89 04 24 b8 00 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 97 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 [ 125.576868] RSP: 002b:00007f5ab20eb580 EFLAGS: 00000293 ORIG_RAX: 0000000000000000 [ 125.578711] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5ab455b51d [ 125.580449] RDX: 0000000000001fa0 RSI: 00007f5ab20ebda0 RDI: 0000000000000004 [ 125.582195] RBP: 0000000000ab32d0 R08: 0000000000000000 R09: 0000000000000000 [ 125.583925] R10: 00007f5ab20eb3d0 R11: 0000000000000293 R12: 00007f5ab20ebda0 [ 125.585713] R13: 0000000000001fa0 R14: 0000000000001f9f R15: 00007f5ab20ebe96 [ 125.587451] Modules linked in: [ 125.588214] CR2: 00000000000003e4 [ 125.589069] BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 [ 125.591006] #PF error: [INSTR] [ 125.591788] PGD 800000022b892067 P4D 800000022b892067 PUD 22b891067 PMD 0 [ 125.593498] Oops: 0010 [#2] SMP PTI [ 125.594373] CPU: 0 PID: 627 Comm: in:imklog Tainted: G D W 5.0.0-rc8+ #9 [ 125.596296] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 [ 125.598536] RIP: 0010: (null) [ 125.599476] Code: Bad RIP value. [ 125.600293] RSP: 0018:ffff9066f7a03d88 EFLAGS: 00010046 [ 125.601602] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 125.603351] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff9066ebb74a38 [ 125.605114] RBP: ffff9066f7a03dd0 R08: 0000000000000000 R09: ffff9066f7a03de8 [ 125.606862] R10: 0000000000000000 R11: 0000000000000000 R12: ffff9066f7a03de8 [ 125.608611] R13: ffffffffffffffe8 R14: ffffffff89a7e018 R15: 0000000000000000 [ 125.610407] FS: 00007f5ab210c700(0000) GS:ffff9066f7a00000(0000) knlGS:0000000000000000 [ 125.612387] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 125.613815] CR2: ffffffffffffffd6 CR3: 000000022beee006 CR4: 00000000000206f0 [ 125.615565] Call Trace: [ 125.616188] <IRQ> [ 125.616712] ? __wake_up_common+0x8c/0x130 [ 125.617747] __wake_up_common_lock+0x80/0xc0 [ 125.618816] __wake_up+0x13/0x20 [ 125.619632] wake_up_klogd_work_func+0x40/0x60 [ 125.620758] irq_work_run_list+0x55/0x80 [ 125.621749] ? tick_sched_do_timer+0x60/0x60 [ 125.622810] irq_work_tick+0x40/0x50 [ 125.623706] update_process_times+0x42/0x60 [ 125.624785] tick_sched_handle+0x29/0x60 [ 125.625762] tick_sched_timer+0x3c/0x80 [ 125.626716] __hrtimer_run_queues+0x106/0x270 [ 125.627798] hrtimer_interrupt+0x116/0x240 [ 125.628828] smp_apic_timer_interrupt+0x6f/0x150 [ 125.629971] apic_timer_interrupt+0xf/0x20 [ 125.630987] </IRQ> [ 125.631526] RIP: 0010:oops_end+0x78/0xf0 [ 125.632503] Code: 7e 99 05 00 8b 05 00 34 d4 01 8d 50 ff 85 d2 89 15 f5 33 d4 01 75 0e 48 c7 c7 ac 64 f7 89 c6 07 00 66 66 66 90 48 89 df 57 9d <66> 66 90 66 90 e8 ee 9d 05 00 be 02 00 00 00 48 c7 c7 c0 64 f7 89 [ 125.637084] RSP: 0018:ffffa8360108fb78 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 [ 125.638935] RAX: 0000000000000001 RBX: 0000000000000246 RCX: 0000000000000006 [ 125.640688] RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000246 [ 125.642442] RBP: ffffa8360108fb90 R08: 0000000000000001 R09: 0000000000000005 [ 125.644176] R10: ffff9066eb2d9500 R11: ffffa8360108fa0d R12: 0000000000000009 [ 125.645965] R13: ffffa8360108fd68 R14: ffff9066eb2d9500 R15: 000000000000000b [ 125.647712] no_context+0x1e9/0x540 [ 125.648584] ? __switch_to_asm+0x40/0x70 [ 125.649568] ? __switch_to_asm+0x34/0x70 [ 125.650537] ? __switch_to_asm+0x40/0x70 [ 125.651512] ? vsnprintf+0x25b/0x4c0 [ 125.652404] __bad_area_nosemaphore+0x50/0x220 [ 125.653513] bad_area+0x46/0x50 [ 125.654298] __do_page_fault+0x386/0x4c0 [ 125.655269] do_page_fault+0x2e/0xf0 [ 125.656162] do_async_page_fault+0x1a/0x80 [ 125.657197] async_page_fault+0x1e/0x30 [ 125.658156] RIP: 0010:fsnotify+0x39a/0x3d0 [ 125.659176] Code: c7 80 65 15 8a 89 45 a8 e8 23 3d e3 ff 8b 45 a8 e9 3e ff ff ff 31 c0 eb e2 48 8b 02 48 8b 58 08 4c 8d 60 e0 8b 80 f8 00 00 00 <0b> 83 e4 03 00 00 e9 d3 fc ff ff 45 31 ff e9 42 fd ff ff 31 c0 e9 [ 125.663731] RSP: 0018:ffffa8360108fe10 EFLAGS: 00010246 [ 125.665039] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000001 [ 125.666790] RDX: ffff9066f3543610 RSI: 0000000000000001 RDI: 0000000000000000 [ 125.668545] RBP: ffffa8360108fe98 R08: 0000000000000000 R09: 0000000000000000 [ 125.670335] R10: ffffc90108bb1a80 R11: ffff9066f7401500 R12: ffff9066ebb4e000 [ 125.672066] R13: 0000000000000001 R14: ffff9066f25102d0 R15: ffff9066f3543610 [ 125.673816] vfs_read+0x127/0x140 [ 125.674641] ksys_read+0x55/0xc0 [ 125.675442] __x64_sys_read+0x1a/0x20 [ 125.676348] do_syscall_64+0x5a/0x110 [ 125.677270] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 125.678523] RIP: 0033:0x7f5ab455b51d [ 125.679417] Code: be 20 00 00 75 10 b8 00 00 00 00 0f 05 48 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 4e fc ff ff 48 89 04 24 b8 00 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 97 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 [ 125.683990] RSP: 002b:00007f5ab20eb580 EFLAGS: 00000293 ORIG_RAX: 0000000000000000 [ 125.685873] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5ab455b51d [ 125.687603] RDX: 0000000000001fa0 RSI: 00007f5ab20ebda0 RDI: 0000000000000004 [ 125.689346] RBP: 0000000000ab32d0 R08: 0000000000000000 R09: 0000000000000000 [ 125.691077] R10: 00007f5ab20eb3d0 R11: 0000000000000293 R12: 00007f5ab20ebda0 [ 125.692848] R13: 0000000000001fa0 R14: 0000000000001f9f R15: 00007f5ab20ebe96 [ 125.694581] Modules linked in: [ 125.695344] CR2: 0000000000000000 [ 125.696170] ---[ end trace b52a1926ac5ee9d4 ]--- [ 125.697320] RIP: 0010:fsnotify+0x39a/0x3d0 [ 125.698327] Code: c7 80 65 15 8a 89 45 a8 e8 23 3d e3 ff 8b 45 a8 e9 3e ff ff ff 31 c0 eb e2 48 8b 02 48 8b 58 08 4c 8d 60 e0 8b 80 f8 00 00 00 <0b> 83 e4 03 00 00 e9 d3 fc ff ff 45 31 ff e9 42 fd ff ff 31 c0 e9 [ 125.702852] RSP: 0018:ffffa8360108fe10 EFLAGS: 00010246 [ 125.704130] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000001 [ 125.705905] RDX: ffff9066f3543610 RSI: 0000000000000001 RDI: 0000000000000000 [ 125.707640] RBP: ffffa8360108fe98 R08: 0000000000000000 R09: 0000000000000000 [ 125.709409] R10: ffffc90108bb1a80 R11: ffff9066f7401500 R12: ffff9066ebb4e000 [ 125.711137] R13: 0000000000000001 R14: ffff9066f25102d0 R15: ffff9066f3543610 [ 125.712881] FS: 00007f5ab210c700(0000) GS:ffff9066f7a00000(0000) knlGS:0000000000000000 [ 125.714838] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 125.716235] CR2: ffffffffffffffd6 CR3: 000000022beee006 CR4: 00000000000206f0 [ 125.718019] Kernel panic - not syncing: Fatal exception in interrupt [ 125.732966] Kernel Offset: 0x7200000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) [ 125.735587] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---
Created attachment 281485 [details] 04.c
Created attachment 281549 [details] Minimized test case Attaching minimized version of program with the same result. (Use this)
Thanks for the report (and all the other reports) It indeed exposes a problem where first key verification is designed to solve, but some other part doesn't co-operate well. With all your script and image, it's not that hard to reproduce. Just a small tip for your later reports, please include previous btrfs error lines. Especially lines like "BTRFS error (device loop0): tree first key mismatch detected, bytenr=29761536 parent_transid=19 key expected=(18446744073709551606,128,79691776) has=(18446744073709551606,128,8798638964736)" will help us to locate the bug in seconds, other than minutes. Thanks, Qu
I see. I will. Thanks.
Thanks for the report. Fixed by 448de471cd4cab0ced "btrfs: Check the first key and level for cached extent buffer" 537f38f019fa0b76 "btrfs: Correctly free extent buffer in case btree_read_extent_buffer_pages fails" , now in 5.2-rc.