================================================================== BUG: KASAN: slab-use-after-free in jfs_readdir+0x1152/0x3420 fs/jfs/jfs_dtree.c:2878 Read of size 8 at addr ffff88805bea9c60 by task syz.7.332/8031 CPU: 1 UID: 0 PID: 8031 Comm: syz.7.332 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 jfs_readdir+0x1152/0x3420 fs/jfs/jfs_dtree.c:2878 wrap_directory_iterator+0x99/0xe0 fs/readdir.c:67 iterate_dir+0x3a5/0x580 fs/readdir.c:110 __do_sys_getdents64 fs/readdir.c:399 [inline] __se_sys_getdents64+0xf1/0x280 fs/readdir.c:384 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f707a66ce59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f70788be028 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 00007f707a8e5fa0 RCX: 00007f707a66ce59 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006 RBP: 00007f707a702d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f707a8e6038 R14: 00007f707a8e5fa0 R15: 00007ffeadf7d6e8 Allocated by task 8031: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4569 [inline] slab_alloc_node mm/slub.c:4898 [inline] kmem_cache_alloc_noprof+0x33b/0x680 mm/slub.c:4905 mempool_alloc_noprof+0x1d4/0x300 mm/mempool.c:566 alloc_metapage fs/jfs/jfs_metapage.c:264 [inline] __get_metapage+0x50c/0xe20 fs/jfs/jfs_metapage.c:761 dtReadFirst+0xbb/0x780 fs/jfs/jfs_dtree.c:3076 dtReadNext fs/jfs/jfs_dtree.c:3157 [inline] jfs_readdir+0x8b7/0x3420 fs/jfs/jfs_dtree.c:2871 wrap_directory_iterator+0x99/0xe0 fs/readdir.c:67 iterate_dir+0x3a5/0x580 fs/readdir.c:110 __do_sys_getdents64 fs/readdir.c:399 [inline] __se_sys_getdents64+0xf1/0x280 fs/readdir.c:384 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 8031: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2689 [inline] slab_free mm/slub.c:6250 [inline] kmem_cache_free+0x187/0x6c0 mm/slub.c:6377 mempool_free+0xf5/0x140 mm/mempool.c:711 free_metapage fs/jfs/jfs_metapage.c:280 [inline] drop_metapage fs/jfs/jfs_metapage.c:317 [inline] release_metapage+0x827/0xa90 fs/jfs/jfs_metapage.c:893 dtReadNext fs/jfs/jfs_dtree.c:3199 [inline] jfs_readdir+0xee3/0x3420 fs/jfs/jfs_dtree.c:2871 wrap_directory_iterator+0x99/0xe0 fs/readdir.c:67 iterate_dir+0x3a5/0x580 fs/readdir.c:110 __do_sys_getdents64 fs/readdir.c:399 [inline] __se_sys_getdents64+0xf1/0x280 fs/readdir.c:384 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88805bea9c30 which belongs to the cache jfs_mp of size 248 The buggy address is located 48 bytes inside of freed 248-byte region [ffff88805bea9c30, ffff88805bea9d28) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5bea9 flags: 0x80000000000000(node=0|zone=1) page_type: f5(slab) raw: 0080000000000000 ffff888140ae0140 dead000000000100 dead000000000122 raw: 0000000000000000 00000008000d000d 00000000f5000000 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 0xd2800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 7885, tgid 7884 (syz.5.298), ts 256639204114, free_ts 256613490195 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1858 prep_new_page mm/page_alloc.c:1866 [inline] get_page_from_freelist+0x27c8/0x2840 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5226 alloc_slab_page mm/slub.c:3278 [inline] allocate_slab+0x77/0x660 mm/slub.c:3467 new_slab mm/slub.c:3525 [inline] refill_objects+0x33c/0x3d0 mm/slub.c:7271 refill_sheaf mm/slub.c:2816 [inline] __pcs_replace_empty_main+0x373/0x720 mm/slub.c:4651 alloc_from_pcs mm/slub.c:4749 [inline] slab_alloc_node mm/slub.c:4883 [inline] kmem_cache_alloc_noprof+0x433/0x680 mm/slub.c:4905 mempool_alloc_noprof+0x1d4/0x300 mm/mempool.c:566 alloc_metapage fs/jfs/jfs_metapage.c:264 [inline] __get_metapage+0x50c/0xe20 fs/jfs/jfs_metapage.c:761 diRead+0x6da/0xb90 fs/jfs/jfs_imap.c:367 jfs_iget+0x89/0x470 fs/jfs/inode.c:35 jfs_fill_super+0x8ad/0xd80 fs/jfs/super.c:547 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3758 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3834 do_mount fs/namespace.c:4167 [inline] __do_sys_mount fs/namespace.c:4383 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4360 page last free pid 5260 tgid 5260 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1402 [inline] __free_frozen_pages+0xfa6/0x10f0 mm/page_alloc.c:2943 __slab_free+0x252/0x2a0 mm/slub.c:5612 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4569 [inline] slab_alloc_node mm/slub.c:4898 [inline] kmem_cache_alloc_node_noprof+0x22a/0x6e0 mm/slub.c:4950 __alloc_skb+0x1d0/0x7d0 net/core/skbuff.c:702 alloc_skb include/linux/skbuff.h:1383 [inline] alloc_skb_with_frags+0xc8/0x760 net/core/skbuff.c:6734 sock_alloc_send_pskb+0x884/0x9a0 net/core/sock.c:2998 unix_dgram_sendmsg+0x460/0x18d0 net/unix/af_unix.c:2141 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] sock_write_iter+0x4a1/0x4f0 net/socket.c:1254 do_iter_readv_writev+0x62b/0x8d0 fs/read_write.c:-1 vfs_writev+0x345/0x9a0 fs/read_write.c:1059 do_writev+0x15a/0x2e0 fs/read_write.c:1105 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88805bea9b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805bea9b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc >ffff88805bea9c00: fc fc fc fc fc fc fa fb fb fb fb fb fb fb fb fb ^ ffff88805bea9c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805bea9d00: fb fb fb fb fb fc fc fc fc fc fc fc fc fa fb fb ==================================================================