On Mon, Oct 29, 2018 at 9:18 PM syzbot <syzbot+4e12d2d56f8ccc65c180@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > syzbot found the following crash on: > > HEAD commit: 9f51ae62c84a Merge git://git.kernel.org/pub/scm/linux/kern.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=130e0599400000 > kernel config: https://syzkaller.appspot.com/x/.config?x=62118286bb772a24 > dashboard link: https://syzkaller.appspot.com/bug?extid=4e12d2d56f8ccc65c180 > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1346e183400000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=117c2713400000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+4e12d2d56f8ccc65c180@xxxxxxxxxxxxxxxxxxxxxxxxx Fix bisection says it was fixed by: #syz fix: media: vb2: add waiting_in_dqbuf flag So let's close the bug, so that it does not hang open on the media subsystem, distracts people and prevents new bugs from being reported. > ================================================================== > BUG: KASAN: use-after-free in __vb2_cleanup_fileio+0x13d/0x160 > drivers/media/common/videobuf2/videobuf2-core.c:2318 > Write of size 4 at addr ffff8801d7730040 by task syz-executor965/5707 > > CPU: 1 PID: 5707 Comm: syz-executor965 Not tainted 4.19.0+ #309 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0x244/0x39d lib/dump_stack.c:113 > print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256 > kasan_report_error mm/kasan/report.c:354 [inline] > kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412 > __asan_report_store4_noabort+0x17/0x20 mm/kasan/report.c:437 > __vb2_cleanup_fileio+0x13d/0x160 > drivers/media/common/videobuf2/videobuf2-core.c:2318 > vb2_core_queue_release+0x1e/0x80 > drivers/media/common/videobuf2/videobuf2-core.c:2043 > vb2_queue_release drivers/media/common/videobuf2/videobuf2-v4l2.c:672 > [inline] > _vb2_fop_release+0x1d2/0x2b0 > drivers/media/common/videobuf2/videobuf2-v4l2.c:843 > vb2_fop_release+0x77/0xc0 > drivers/media/common/videobuf2/videobuf2-v4l2.c:857 > vivid_fop_release+0x18e/0x440 drivers/media/platform/vivid/vivid-core.c:474 > v4l2_release+0xfb/0x1a0 drivers/media/v4l2-core/v4l2-dev.c:448 > __fput+0x385/0xa30 fs/file_table.c:278 > ____fput+0x15/0x20 fs/file_table.c:309 > task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 > tracehook_notify_resume include/linux/tracehook.h:188 [inline] > exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166 > prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] > syscall_return_slowpath arch/x86/entry/common.c:268 [inline] > do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x400f30 > Code: 01 f0 ff ff 0f 83 b0 0a 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f > 44 00 00 83 3d 9d 57 2d 00 00 75 14 b8 03 00 00 00 0f 05 <48> 3d 01 f0 ff > ff 0f 83 84 0a 00 00 c3 48 83 ec 08 e8 3a 01 00 00 > RSP: 002b:00007ffd05f62478 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 > RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000400f30 > RDX: 0000000000000001 RSI: 0000000020000280 RDI: 0000000000000003 > RBP: 0000000000000000 R08: 00000000004002e0 R09: 00000000004002e0 > R10: 0000000000a73880 R11: 0000000000000246 R12: 0000000000401e40 > R13: 0000000000401ed0 R14: 0000000000000000 R15: 0000000000000000 > > Allocated by task 5702: > save_stack+0x43/0xd0 mm/kasan/kasan.c:448 > set_track mm/kasan/kasan.c:460 [inline] > kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553 > kmem_cache_alloc_trace+0x152/0x750 mm/slab.c:3620 > kmalloc include/linux/slab.h:546 [inline] > kzalloc include/linux/slab.h:741 [inline] > __vb2_init_fileio+0x1ce/0xc90 > drivers/media/common/videobuf2/videobuf2-core.c:2227 > __vb2_perform_fileio+0xcfb/0x1210 > drivers/media/common/videobuf2/videobuf2-core.c:2361 > vb2_read+0x3b/0x50 drivers/media/common/videobuf2/videobuf2-core.c:2493 > vb2_fop_read+0x20a/0x400 > drivers/media/common/videobuf2/videobuf2-v4l2.c:898 > v4l2_read+0x168/0x220 drivers/media/v4l2-core/v4l2-dev.c:317 > do_loop_readv_writev fs/read_write.c:700 [inline] > do_iter_read+0x4a3/0x650 fs/read_write.c:924 > vfs_readv+0x175/0x1c0 fs/read_write.c:986 > do_readv+0x11a/0x310 fs/read_write.c:1019 > __do_sys_readv fs/read_write.c:1106 [inline] > __se_sys_readv fs/read_write.c:1103 [inline] > __x64_sys_readv+0x75/0xb0 fs/read_write.c:1103 > do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > Freed by task 5702: > save_stack+0x43/0xd0 mm/kasan/kasan.c:448 > set_track mm/kasan/kasan.c:460 [inline] > __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 > kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 > __cache_free mm/slab.c:3498 [inline] > kfree+0xcf/0x230 mm/slab.c:3817 > __vb2_cleanup_fileio+0xf8/0x160 > drivers/media/common/videobuf2/videobuf2-core.c:2320 > vb2_core_queue_release+0x1e/0x80 > drivers/media/common/videobuf2/videobuf2-core.c:2043 > vb2_queue_release drivers/media/common/videobuf2/videobuf2-v4l2.c:672 > [inline] > _vb2_fop_release+0x1d2/0x2b0 > drivers/media/common/videobuf2/videobuf2-v4l2.c:843 > vb2_fop_release+0x77/0xc0 > drivers/media/common/videobuf2/videobuf2-v4l2.c:857 > vivid_fop_release+0x18e/0x440 drivers/media/platform/vivid/vivid-core.c:474 > v4l2_release+0xfb/0x1a0 drivers/media/v4l2-core/v4l2-dev.c:448 > __fput+0x385/0xa30 fs/file_table.c:278 > ____fput+0x15/0x20 fs/file_table.c:309 > task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 > tracehook_notify_resume include/linux/tracehook.h:188 [inline] > exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166 > prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] > syscall_return_slowpath arch/x86/entry/common.c:268 [inline] > do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > The buggy address belongs to the object at ffff8801d7730040 > which belongs to the cache kmalloc-1k of size 1024 > The buggy address is located 0 bytes inside of > 1024-byte region [ffff8801d7730040, ffff8801d7730440) > The buggy address belongs to the page: > page:ffffea00075dcc00 count:1 mapcount:0 mapping:ffff8801da800ac0 index:0x0 > compound_mapcount: 0 > flags: 0x2fffc0000010200(slab|head) > raw: 02fffc0000010200 ffffea00075dcb88 ffffea00075dde08 ffff8801da800ac0 > raw: 0000000000000000 ffff8801d7730040 0000000100000007 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff8801d772ff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > ffff8801d772ff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > > ffff8801d7730000: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb > ^ > ffff8801d7730080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff8801d7730100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ================================================================== > > > --- > This bug is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this bug report. See: > https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with > syzbot. > syzbot can test patches for this bug, for details see: > https://goo.gl/tpsmEJ#testing-patches > > -- > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@xxxxxxxxxxxxxxxx. > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/000000000000204051057963c4dc%40google.com. > For more options, visit https://groups.google.com/d/optout.
