Hello, syzbot found the following issue on: HEAD commit: 28c736b0e92e Add linux-next specific files for 20230822 git tree: linux-next console+strace: https://syzkaller.appspot.com/x/log.txt?x=11400507a80000 kernel config: https://syzkaller.appspot.com/x/.config?x=20999f779fa96017 dashboard link: https://syzkaller.appspot.com/bug?extid=2b8cbfa6e34e51b6aa50 compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1298bdd3a80000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11adcca7a80000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/37bc881cd0b2/disk-28c736b0.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/4512f7892b3d/vmlinux-28c736b0.xz kernel image: https://storage.googleapis.com/syzbot-assets/052fe1287e05/bzImage-28c736b0.xz The issue was bisected to: commit 2c18a63b760a0f68f14cb8bb4c3840bb0b63b73e Author: Christian Brauner <brauner@xxxxxxxxxx> Date: Fri Aug 18 14:00:51 2023 +0000 super: wait until we passed kill super bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1593bd97a80000 final oops: https://syzkaller.appspot.com/x/report.txt?x=1793bd97a80000 console output: https://syzkaller.appspot.com/x/log.txt?x=1393bd97a80000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+2b8cbfa6e34e51b6aa50@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: 2c18a63b760a ("super: wait until we passed kill super") ================================================================== BUG: KASAN: slab-use-after-free in memcmp+0x1b5/0x1c0 lib/string.c:681 Read of size 8 at addr ffff8880772b2780 by task syz-executor410/5427 CPU: 0 PID: 5427 Comm: syz-executor410 Not tainted 6.5.0-rc7-next-20230822-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 Call Trace: <TASK> __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:1713 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_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 RIP: 0033:0x7fc6399b13d9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 18 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc639972238 EFLAGS: 00000246 ORIG_RAX: 00000000000001af RAX: ffffffffffffffda RBX: 00007fc639a3b328 RCX: 00007fc6399b13d9 RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000003 RBP: 00007fc639a3b320 R08: 0000000000000000 R09: 00007fc6399726c0 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc639a08064 R13: 0000000000000000 R14: 00007fffb7a44050 R15: 00007fffb7a44138 </TASK> Allocated by task 5415: 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:599 [inline] kzalloc include/linux/slab.h:720 [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] __x64_sys_fsopen+0xeb/0x230 fs/fsopen.c:115 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 Freed by task 5415: 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+0x15b/0x1b0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1800 [inline] slab_free_freelist_hook+0x114/0x1e0 mm/slub.c:1826 slab_free mm/slub.c:3809 [inline] __kmem_cache_free+0xb8/0x2f0 mm/slub.c:3822 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:1713 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_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 The buggy address belongs to the object at ffff8880772b2780 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 0 bytes inside of freed 96-byte region [ffff8880772b2780, ffff8880772b27e0) The buggy address belongs to the physical page: page:ffffea0001dcac80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x772b2 flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000800 ffff888012c41780 dead000000000122 0000000000000000 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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 5404, tgid 5400 (syz-executor410), ts 75501157693, free_ts 75473204266 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2cf/0x340 mm/page_alloc.c:1530 prep_new_page mm/page_alloc.c:1537 [inline] get_page_from_freelist+0x10d7/0x31b0 mm/page_alloc.c:3213 __alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4469 alloc_pages+0x1a9/0x270 mm/mempolicy.c:2298 alloc_slab_page mm/slub.c:1870 [inline] allocate_slab+0x251/0x380 mm/slub.c:2017 new_slab mm/slub.c:2070 [inline] ___slab_alloc+0x8be/0x1570 mm/slub.c:3223 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3322 __slab_alloc_node mm/slub.c:3375 [inline] slab_alloc_node mm/slub.c:3468 [inline] __kmem_cache_alloc_node+0x137/0x350 mm/slub.c:3517 __do_kmalloc_node mm/slab_common.c:1022 [inline] __kmalloc+0x4f/0x100 mm/slab_common.c:1036 kmalloc_array include/linux/slab.h:636 [inline] ceph_msg_new2+0x34e/0x4f0 net/ceph/messenger.c:1916 msgpool_alloc+0xa8/0x1c0 net/ceph/msgpool.c:17 mempool_init_node+0x2ec/0x5a0 mm/mempool.c:207 mempool_create_node mm/mempool.c:276 [inline] mempool_create+0x7f/0xd0 mm/mempool.c:261 ceph_msgpool_init+0xd0/0x190 net/ceph/msgpool.c:46 ceph_osdc_init+0x6f9/0xc60 net/ceph/osd_client.c:5193 ceph_create_client net/ceph/ceph_common.c:745 [inline] ceph_create_client+0x27e/0x360 net/ceph/ceph_common.c:707 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1130 [inline] free_unref_page_prepare+0x476/0xa40 mm/page_alloc.c:2342 free_unref_page_list+0xe6/0xb30 mm/page_alloc.c:2481 release_pages+0x32a/0x14e0 mm/swap.c:1042 tlb_batch_pages_flush+0x9a/0x190 mm/mmu_gather.c:98 tlb_flush_mmu_free mm/mmu_gather.c:293 [inline] tlb_flush_mmu mm/mmu_gather.c:300 [inline] tlb_finish_mmu+0x14b/0x6f0 mm/mmu_gather.c:392 exit_mmap+0x38b/0xa60 mm/mmap.c:3223 __mmput+0x12a/0x4d0 kernel/fork.c:1356 mmput+0x62/0x70 kernel/fork.c:1378 exit_mm kernel/exit.c:567 [inline] do_exit+0x9b4/0x2a20 kernel/exit.c:861 do_group_exit+0xd4/0x2a0 kernel/exit.c:1024 get_signal+0x23d1/0x27b0 kernel/signal.c:2892 arch_do_signal_or_restart+0x90/0x7f0 arch/x86/kernel/signal.c:309 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x1d/0x60 kernel/entry/common.c:297 do_syscall_64+0x44/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff8880772b2680: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff8880772b2700: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff8880772b2780: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff8880772b2800: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc ffff8880772b2880: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ================================================================== --- This report 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 issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. For information about bisection process see: https://goo.gl/tpsmEJ#bisection If the bug is already fixed, let syzbot know by replying with: #syz fix: exact-commit-title If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing. If you want to overwrite bug's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the bug is a duplicate of another bug, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
