================================================================== BUG: KASAN: slab-use-after-free in memcmp+0x1b5/0x1c0 lib/string.c:681 Read of size 8 at addr ffff888023d1d600 by task syz-executor.2/1314 CPU: 3 PID: 1314 Comm: syz-executor.2 Not tainted 6.5.0-syzkaller-01207-g1c59d383390f #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xc4/0x620 mm/kasan/report.c:475 kasan_report+0xda/0x110 mm/kasan/report.c:588 memcmp+0x1b5/0x1c0 lib/string.c:681 memcmp include/linux/fortify-string.h:728 [inline] compare_mount_options fs/ceph/super.c:622 [inline] ceph_compare_super+0x11a/0x8d0 fs/ceph/super.c:1147 sget_fc+0x582/0x9b0 fs/super.c:778 ceph_get_tree+0x6ea/0x1910 fs/ceph/super.c:1232 vfs_get_tree+0x8c/0x370 fs/super.c:1711 vfs_cmd_create+0x11f/0x2f0 fs/fsopen.c:230 vfs_fsconfig_locked fs/fsopen.c:294 [inline] __do_sys_fsconfig+0x832/0xb90 fs/fsopen.c:475 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x61/0xe0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 RIP: 0023:0xf7f3a579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f7f355ac EFLAGS: 00000292 ORIG_RAX: 00000000000001af RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000000006 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 1303: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:383 kmalloc include/linux/slab.h:582 [inline] kzalloc include/linux/slab.h:703 [inline] ceph_init_fs_context+0xc8/0x530 fs/ceph/super.c:1333 alloc_fs_context+0x56c/0x9f0 fs/fs_context.c:294 __do_sys_fsopen fs/fsopen.c:137 [inline] __se_sys_fsopen fs/fsopen.c:115 [inline] __ia32_sys_fsopen+0xef/0x230 fs/fsopen.c:115 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x61/0xe0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 Freed by task 1303: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:522 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x15e/0x1b0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:162 [inline] slab_free_hook mm/slub.c:1792 [inline] slab_free_freelist_hook+0x10b/0x1e0 mm/slub.c:1818 slab_free mm/slub.c:3801 [inline] __kmem_cache_free+0xb8/0x2f0 mm/slub.c:3814 destroy_mount_options fs/ceph/super.c:599 [inline] destroy_mount_options+0xe9/0x140 fs/ceph/super.c:588 destroy_fs_client+0x1b6/0x2b0 fs/ceph/super.c:860 deactivate_locked_super+0xa0/0x2d0 fs/super.c:454 ceph_get_tree+0x1270/0x1910 fs/ceph/super.c:1267 vfs_get_tree+0x8c/0x370 fs/super.c:1711 vfs_cmd_create+0x11f/0x2f0 fs/fsopen.c:230 vfs_fsconfig_locked fs/fsopen.c:294 [inline] __do_sys_fsconfig+0x832/0xb90 fs/fsopen.c:475 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x61/0xe0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 Last potentially related work creation: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:492 __call_rcu_common.constprop.0+0x9a/0x790 kernel/rcu/tree.c:2653 release_callchain_buffers kernel/events/callchain.c:67 [inline] put_callchain_buffers+0x55/0x70 kernel/events/callchain.c:147 bpf_map_free_deferred+0x192/0x3c0 kernel/bpf/syscall.c:698 process_one_work+0xaa2/0x16f0 kernel/workqueue.c:2600 worker_thread+0x687/0x1110 kernel/workqueue.c:2751 kthread+0x33a/0x430 kernel/kthread.c:389 ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:145 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 The buggy address belongs to the object at ffff888023d1d600 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 0 bytes inside of freed 96-byte region [ffff888023d1d600, ffff888023d1d660) The buggy address belongs to the physical page: page:ffffea00008f4740 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x23d1d flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000200 ffff888012842780 ffffea00006e1680 dead000000000002 raw: 0000000000000000 0000000000200020 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 17381, tgid 17381 (syz-executor.0), ts 463502852014, free_ts 463497013158 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2d2/0x350 mm/page_alloc.c:1570 prep_new_page mm/page_alloc.c:1577 [inline] get_page_from_freelist+0x10a9/0x31e0 mm/page_alloc.c:3221 __alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4477 __alloc_pages_node include/linux/gfp.h:237 [inline] alloc_slab_page mm/slub.c:1864 [inline] allocate_slab+0xa1/0x380 mm/slub.c:2009 new_slab mm/slub.c:2062 [inline] ___slab_alloc+0x8bc/0x1570 mm/slub.c:3215 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3314 __slab_alloc_node mm/slub.c:3367 [inline] slab_alloc_node mm/slub.c:3460 [inline] __kmem_cache_alloc_node+0x137/0x350 mm/slub.c:3509 __do_kmalloc_node mm/slab_common.c:984 [inline] __kmalloc_node+0x4f/0x100 mm/slab_common.c:992 kmalloc_array_node include/linux/slab.h:680 [inline] kcalloc_node include/linux/slab.h:685 [inline] memcg_alloc_slab_cgroups+0xa9/0x170 mm/memcontrol.c:2899 account_slab mm/slab.h:636 [inline] allocate_slab+0x2c7/0x380 mm/slub.c:2027 new_slab mm/slub.c:2062 [inline] ___slab_alloc+0x8bc/0x1570 mm/slub.c:3215 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3314 __slab_alloc_node mm/slub.c:3367 [inline] slab_alloc_node mm/slub.c:3460 [inline] slab_alloc mm/slub.c:3478 [inline] __kmem_cache_alloc_lru mm/slub.c:3485 [inline] kmem_cache_alloc_lru+0x4e4/0x630 mm/slub.c:3501 alloc_inode_sb include/linux/fs.h:2908 [inline] ext4_alloc_inode+0x28/0x650 fs/ext4/super.c:1360 alloc_inode+0x5d/0x220 fs/inode.c:259 new_inode_pseudo fs/inode.c:1004 [inline] new_inode+0x22/0x260 fs/inode.c:1030 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1161 [inline] free_unref_page_prepare+0x508/0xb90 mm/page_alloc.c:2348 free_unref_page+0x33/0x3b0 mm/page_alloc.c:2443 __folio_put_small mm/swap.c:106 [inline] __folio_put+0xc5/0x140 mm/swap.c:129 folio_put include/linux/mm.h:1440 [inline] put_page include/linux/mm.h:1509 [inline] anon_pipe_buf_release+0x3fa/0x4b0 fs/pipe.c:138 pipe_buf_release include/linux/pipe_fs_i.h:203 [inline] pipe_read+0x635/0x1270 fs/pipe.c:324 call_read_iter include/linux/fs.h:1979 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x7ef/0x930 fs/read_write.c:470 ksys_read+0x1f0/0x250 fs/read_write.c:613 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff888023d1d500: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff888023d1d580: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff888023d1d600: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff888023d1d680: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff888023d1d700: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ================================================================== ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 ret 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi