Messages in this thread | | | Date | Mon, 24 Feb 2020 10:35:30 -0800 | From | Eric Biggers <> | Subject | Re: KASAN: use-after-free Read in tty_buffer_cancel_work |
| |
On Mon, Dec 23, 2019 at 09:31:08AM -0800, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: 7e0165b2 Merge branch 'akpm' (patches from Andrew) > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=154494c1e00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=1b59a3066828ac4c > dashboard link: https://syzkaller.appspot.com/bug?extid=bd5f8de9deae03ace6a6 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > > Unfortunately, I don't have any reproducer for this crash yet. > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+bd5f8de9deae03ace6a6@syzkaller.appspotmail.com > > ================================================================== > BUG: KASAN: use-after-free in atomic64_read > include/asm-generic/atomic-instrumented.h:836 [inline] > BUG: KASAN: use-after-free in atomic_long_read > include/asm-generic/atomic-long.h:28 [inline] > BUG: KASAN: use-after-free in work_is_canceling kernel/workqueue.c:751 > [inline] > BUG: KASAN: use-after-free in __cancel_work_timer+0x433/0x540 > kernel/workqueue.c:3113 > Read of size 8 at addr ffff8880a77fc008 by task syz-executor.0/16211 > > CPU: 1 PID: 16211 Comm: syz-executor.0 Not tainted 5.5.0-rc2-syzkaller #0 > 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+0x197/0x210 lib/dump_stack.c:118 > print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374 > __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506 > kasan_report+0x12/0x20 mm/kasan/common.c:639 > check_memory_region_inline mm/kasan/generic.c:185 [inline] > check_memory_region+0x134/0x1a0 mm/kasan/generic.c:192 > __kasan_check_read+0x11/0x20 mm/kasan/common.c:95 > atomic64_read include/asm-generic/atomic-instrumented.h:836 [inline] > atomic_long_read include/asm-generic/atomic-long.h:28 [inline] > work_is_canceling kernel/workqueue.c:751 [inline] > __cancel_work_timer+0x433/0x540 kernel/workqueue.c:3113 > cancel_work_sync+0x18/0x20 kernel/workqueue.c:3164 > tty_buffer_cancel_work+0x16/0x20 drivers/tty/tty_buffer.c:613 > release_tty+0x261/0x470 drivers/tty/tty_io.c:1520 > tty_release_struct+0x3c/0x50 drivers/tty/tty_io.c:1629 > tty_release+0xbcb/0xe90 drivers/tty/tty_io.c:1789 > __fput+0x2ff/0x890 fs/file_table.c:280 > ____fput+0x16/0x20 fs/file_table.c:313 > task_work_run+0x145/0x1c0 kernel/task_work.c:113 > tracehook_notify_resume include/linux/tracehook.h:188 [inline] > exit_to_usermode_loop+0x316/0x380 arch/x86/entry/common.c:164 > prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] > syscall_return_slowpath arch/x86/entry/common.c:278 [inline] > do_syscall_64+0x676/0x790 arch/x86/entry/common.c:304 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x4144b1 > Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 1b 00 00 c3 48 > 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 > c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 > RSP: 002b:00007fff1f1c15d0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 > RAX: 0000000000000000 RBX: 0000000000000004 RCX: 00000000004144b1 > RDX: 0000001b30420000 RSI: 0000000000000000 RDI: 0000000000000003 > RBP: 0000000000000001 R08: 00000000b81729f0 R09: 00000000b81729f4 > R10: 00007fff1f1c16b0 R11: 0000000000000293 R12: 000000000075bf20 > R13: 000000000005bac3 R14: 0000000000760180 R15: 000000000075bf2c > > Allocated by task 16213: > save_stack+0x23/0x90 mm/kasan/common.c:72 > set_track mm/kasan/common.c:80 [inline] > __kasan_kmalloc mm/kasan/common.c:513 [inline] > __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:486 > kasan_kmalloc+0x9/0x10 mm/kasan/common.c:527 > kmem_cache_alloc_trace+0x158/0x790 mm/slab.c:3551 > kmalloc include/linux/slab.h:556 [inline] > kzalloc include/linux/slab.h:670 [inline] > vc_allocate drivers/tty/vt/vt.c:1085 [inline] > vc_allocate+0x1fc/0x760 drivers/tty/vt/vt.c:1066 > con_install+0x52/0x410 drivers/tty/vt/vt.c:3229 > tty_driver_install_tty drivers/tty/tty_io.c:1228 [inline] > tty_init_dev drivers/tty/tty_io.c:1341 [inline] > tty_init_dev+0xf9/0x470 drivers/tty/tty_io.c:1318 > tty_open_by_driver drivers/tty/tty_io.c:1987 [inline] > tty_open+0x4a5/0xbb0 drivers/tty/tty_io.c:2035 > chrdev_open+0x245/0x6b0 fs/char_dev.c:414 > do_dentry_open+0x4e6/0x1380 fs/open.c:797 > vfs_open+0xa0/0xd0 fs/open.c:914 > do_last fs/namei.c:3420 [inline] > path_openat+0x10df/0x4500 fs/namei.c:3537 > do_filp_open+0x1a1/0x280 fs/namei.c:3567 > do_sys_open+0x3fe/0x5d0 fs/open.c:1097 > __do_sys_open fs/open.c:1115 [inline] > __se_sys_open fs/open.c:1110 [inline] > __x64_sys_open+0x7e/0xc0 fs/open.c:1110 > do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > Freed by task 16188: > save_stack+0x23/0x90 mm/kasan/common.c:72 > set_track mm/kasan/common.c:80 [inline] > kasan_set_free_info mm/kasan/common.c:335 [inline] > __kasan_slab_free+0x102/0x150 mm/kasan/common.c:474 > kasan_slab_free+0xe/0x10 mm/kasan/common.c:483 > __cache_free mm/slab.c:3426 [inline] > kfree+0x10a/0x2c0 mm/slab.c:3757 > vt_disallocate_all+0x2bd/0x3e0 drivers/tty/vt/vt_ioctl.c:323 > vt_ioctl+0xc38/0x26d0 drivers/tty/vt/vt_ioctl.c:816 > tty_ioctl+0xa37/0x14f0 drivers/tty/tty_io.c:2660 > vfs_ioctl fs/ioctl.c:47 [inline] > file_ioctl fs/ioctl.c:545 [inline] > do_vfs_ioctl+0x977/0x14e0 fs/ioctl.c:732 > ksys_ioctl+0xab/0xd0 fs/ioctl.c:749 > __do_sys_ioctl fs/ioctl.c:756 [inline] > __se_sys_ioctl fs/ioctl.c:754 [inline] > __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:754 > do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > The buggy address belongs to the object at ffff8880a77fc000 > which belongs to the cache kmalloc-2k of size 2048 > The buggy address is located 8 bytes inside of > 2048-byte region [ffff8880a77fc000, ffff8880a77fc800) > The buggy address belongs to the page: > page:ffffea00029dff00 refcount:1 mapcount:0 mapping:ffff8880aa400e00 > index:0x0 > raw: 00fffe0000000200 ffffea000251ef08 ffffea00029b5008 ffff8880aa400e00 > raw: 0000000000000000 ffff8880a77fc000 0000000100000001 0000000000000000 > page dumped because: kasan: bad access detected >
#syz dup: KASAN: use-after-free Write in release_tty
(Thread link: https://lkml.kernel.org/lkml/0000000000006663de0598d25ab1@google.com/)
| |