On Sat, Mar 31, 2018 at 01:47:05PM -0700, syzbot wrote: > Hello, > > syzbot hit the following crash on upstream commit > 9dd2326890d89a5179967c947dab2bab34d7ddee (Fri Mar 30 17:29:47 2018 +0000) > Merge tag 'ceph-for-4.16-rc8' of git://github.com/ceph/ceph-client > syzbot dashboard link: > https://syzkaller.appspot.com/bug?extid=040b31ac96753fd7eb46 > > So far this crash happened 50 times on upstream. > C reproducer: https://syzkaller.appspot.com/x/repro.c?id=6534913729757184 > syzkaller reproducer: > https://syzkaller.appspot.com/x/repro.syz?id=6221692233842688 > Raw console output: > https://syzkaller.appspot.com/x/log.txt?id=5252920484298752 > Kernel config: > https://syzkaller.appspot.com/x/.config?id=-2760467897697295172 > compiler: gcc (GCC) 7.1.1 20170620 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+040b31ac96753fd7eb46@xxxxxxxxxxxxxxxxxxxxxxxxx > It will help syzbot understand when the bug is fixed. See footer for > details. > If you forward the report, please keep this part and the footer. > > IPVS: ftp: loaded support on port[0] = 21 > XFS (loop5): Invalid device [./file0], error=-15 > XFS (loop7): nobarrier option is deprecated, ignoring. > XFS (loop7): Invalid device [./file0], error=-15 > ================================================================== > BUG: KASAN: use-after-free in radix_tree_next_chunk+0xde1/0xdf0 > lib/radix-tree.c:1733 > Read of size 4 at addr ffff8801b1669250 by task syzkaller476032/4458 > > CPU: 1 PID: 4458 Comm: syzkaller476032 Not tainted 4.16.0-rc7+ #7 > IPVS: ftp: loaded support on port[0] = 21 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:17 [inline] > dump_stack+0x194/0x24d lib/dump_stack.c:53 > print_address_description+0x73/0x250 mm/kasan/report.c:256 > kasan_report_error mm/kasan/report.c:354 [inline] > kasan_report+0x23c/0x360 mm/kasan/report.c:412 > __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432 > radix_tree_next_chunk+0xde1/0xdf0 lib/radix-tree.c:1733 > radix_tree_gang_lookup_tag+0x36e/0x5e0 lib/radix-tree.c:1918 > IPVS: ftp: loaded support on port[0] = 21 > xfs_perag_get_tag+0x109/0x6c0 fs/xfs/libxfs/xfs_sb.c:88 > IPVS: ftp: loaded support on port[0] = 21 > xfs_reclaim_inodes_count+0x82/0xb0 fs/xfs/xfs_icache.c:1362 > xfs_fs_nr_cached_objects+0x37/0x50 fs/xfs/xfs_super.c:1778 > super_cache_count+0x96/0x280 fs/super.c:131 > do_shrink_slab mm/vmscan.c:310 [inline] > shrink_slab.part.46+0x30c/0xe80 mm/vmscan.c:475 > shrink_slab+0x9d/0xb0 mm/vmscan.c:442 > shrink_node+0x51e/0xf70 mm/vmscan.c:2556 > shrink_zones mm/vmscan.c:2728 [inline] > do_try_to_free_pages+0x383/0x1020 mm/vmscan.c:2790 > try_to_free_mem_cgroup_pages+0x44d/0xb40 mm/vmscan.c:3079 > IPVS: ftp: loaded support on port[0] = 21 > reclaim_high.constprop.64+0x1e2/0x330 mm/memcontrol.c:1862 > IPVS: ftp: loaded support on port[0] = 21 > mem_cgroup_handle_over_high+0x8d/0x130 mm/memcontrol.c:1887 > tracehook_notify_resume include/linux/tracehook.h:193 [inline] > exit_to_usermode_loop+0x242/0x2f0 arch/x86/entry/common.c:166 > prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] > syscall_return_slowpath arch/x86/entry/common.c:265 [inline] > do_syscall_64+0x6ec/0x940 arch/x86/entry/common.c:292 > entry_SYSCALL_64_after_hwframe+0x42/0xb7 > RIP: 0033:0x440fda > RSP: 002b:00007ffd309f1880 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 > RAX: 0000000000000003 RBX: 0000000000000000 RCX: 0000000000440fda > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 > RBP: 00007ffd309f18a0 R08: 0000000000000001 R09: 00000000020eb880 > R10: 00000000020ebb50 R11: 0000000000000246 R12: 0000000000000001 > R13: 00007ffd309f18d0 R14: 0000000000000000 R15: 00007ffd309f19e8 > > Allocated by task 4469: > save_stack+0x43/0xd0 mm/kasan/kasan.c:447 > set_track mm/kasan/kasan.c:459 [inline] > kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:552 > kmem_cache_alloc_trace+0x136/0x740 mm/slab.c:3608 > kmalloc include/linux/slab.h:512 [inline] > kzalloc include/linux/slab.h:701 [inline] > xfs_fs_fill_super+0xd1/0x1220 fs/xfs/xfs_super.c:1579 > mount_bdev+0x2b7/0x370 fs/super.c:1119 > xfs_fs_mount+0x34/0x40 fs/xfs/xfs_super.c:1770 > mount_fs+0x66/0x2d0 fs/super.c:1222 > vfs_kern_mount.part.26+0xc6/0x4a0 fs/namespace.c:1037 > vfs_kern_mount fs/namespace.c:2509 [inline] > do_new_mount fs/namespace.c:2512 [inline] > do_mount+0xea4/0x2bb0 fs/namespace.c:2842 > SYSC_mount fs/namespace.c:3058 [inline] > SyS_mount+0xab/0x120 fs/namespace.c:3035 > do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 > entry_SYSCALL_64_after_hwframe+0x42/0xb7 > > Freed by task 4469: > save_stack+0x43/0xd0 mm/kasan/kasan.c:447 > set_track mm/kasan/kasan.c:459 [inline] > __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:520 > kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:527 > __cache_free mm/slab.c:3486 [inline] > kfree+0xd9/0x260 mm/slab.c:3801 > xfs_fs_fill_super+0x6c3/0x1220 fs/xfs/xfs_super.c:1734 > mount_bdev+0x2b7/0x370 fs/super.c:1119 > xfs_fs_mount+0x34/0x40 fs/xfs/xfs_super.c:1770 > mount_fs+0x66/0x2d0 fs/super.c:1222 > vfs_kern_mount.part.26+0xc6/0x4a0 fs/namespace.c:1037 > vfs_kern_mount fs/namespace.c:2509 [inline] > do_new_mount fs/namespace.c:2512 [inline] > do_mount+0xea4/0x2bb0 fs/namespace.c:2842 > SYSC_mount fs/namespace.c:3058 [inline] > SyS_mount+0xab/0x120 fs/namespace.c:3035 > do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 > entry_SYSCALL_64_after_hwframe+0x42/0xb7 > > The buggy address belongs to the object at ffff8801b1668e80 > which belongs to the cache kmalloc-4096 of size 4096 > The buggy address is located 976 bytes inside of > 4096-byte region [ffff8801b1668e80, ffff8801b1669e80) > The buggy address belongs to the page: > page:ffffea0006c59a00 count:1 mapcount:0 mapping:ffff8801b1668e80 index:0x0 > compound_mapcount: 0 > flags: 0x2fffc0000008100(slab|head) > raw: 02fffc0000008100 ffff8801b1668e80 0000000000000000 0000000100000001 > raw: ffffea0006c5a2a0 ffffea0006cc47a0 ffff8801dac00dc0 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff8801b1669100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff8801b1669180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ffff8801b1669200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ^ > ffff8801b1669280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff8801b1669300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ================================================================== > > > --- > This bug is generated by a dumb bot. It may contain errors. > See https://goo.gl/tpsmEJ for details. > Direct all questions to syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this bug report. > If you forgot to add the Reported-by tag, once the fix for this bug is > merged > into any tree, please reply to this email with: > #syz fix: exact-commit-title This was fixed by commit 79f546a696bff2: #syz fix: fs: don't scan the inode cache before SB_BORN is set - Eric -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
