loop0: detected capacity change from 0 to 32768 ================================================================== BUG: KASAN: use-after-free in jfs_readdir+0x127e/0x3d40 fs/jfs/jfs_dtree.c:3179 Read of size 8 at addr ffff8880742cebd0 by task syz.0.17/5169 CPU: 0 PID: 5169 Comm: syz.0.17 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 print_address_description+0x60/0x2d0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xdf/0x130 mm/kasan/report.c:451 jfs_readdir+0x127e/0x3d40 fs/jfs/jfs_dtree.c:3179 iterate_dir+0x213/0x550 fs/readdir.c:-1 __do_sys_getdents fs/readdir.c:286 [inline] __se_sys_getdents+0xf2/0x260 fs/readdir.c:271 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f5a90b04379 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:00007f5a90168028 EFLAGS: 00000246 ORIG_RAX: 000000000000004e RAX: ffffffffffffffda RBX: 00007f5a90d5ffa0 RCX: 00007f5a90b04379 RDX: fffffffffffffd90 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00007f5a90b97d68 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5a90d60038 R14: 00007f5a90d5ffa0 R15: 00007ffcc16b6988 Allocated by task 5169: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x92/0xc0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3225 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc+0x15d/0x280 mm/slub.c:3238 mempool_alloc+0x19d/0x510 mm/mempool.c:393 alloc_metapage fs/jfs/jfs_metapage.c:175 [inline] __get_metapage+0x5e8/0x1060 fs/jfs/jfs_metapage.c:652 dtSplitRoot+0x1cb/0x14d0 fs/jfs/jfs_dtree.c:1910 dtSplitUp fs/jfs/jfs_dtree.c:993 [inline] dtInsert+0xe84/0x57e0 fs/jfs/jfs_dtree.c:871 jfs_symlink+0x8bb/0xfd0 fs/jfs/namei.c:1019 vfs_symlink+0x245/0x3d0 fs/namei.c:4437 do_symlinkat+0x1ab/0x6b0 fs/namei.c:4466 __do_sys_symlink fs/namei.c:4488 [inline] __se_sys_symlink fs/namei.c:4486 [inline] __x64_sys_symlink+0x7a/0x90 fs/namei.c:4486 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Freed by task 5169: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1710 [inline] slab_free_freelist_hook+0xec/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kmem_cache_free+0x8f/0x210 mm/slub.c:3520 free_metapage fs/jfs/jfs_metapage.c:190 [inline] drop_metapage fs/jfs/jfs_metapage.c:227 [inline] release_metapage+0x9c6/0xda0 fs/jfs/jfs_metapage.c:758 dtReadNext fs/jfs/jfs_dtree.c:3500 [inline] jfs_readdir+0x1008/0x3d40 fs/jfs/jfs_dtree.c:3172 iterate_dir+0x213/0x550 fs/readdir.c:-1 __do_sys_getdents fs/readdir.c:286 [inline] __se_sys_getdents+0xf2/0x260 fs/readdir.c:271 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 The buggy address belongs to the object at ffff8880742ceba0 which belongs to the cache jfs_mp of size 184 The buggy address is located 48 bytes inside of 184-byte region [ffff8880742ceba0, ffff8880742cec58) The buggy address belongs to the page: page:ffffea0001d0b380 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x742ce flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 0000000000000000 dead000000000122 ffff888146806dc0 raw: 0000000000000000 0000000080100010 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 0x192800(GFP_NOWAIT|__GFP_NOWARN|__GFP_NORETRY|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5169, ts 107057234371, free_ts 106925524564 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x24f6/0x2670 mm/page_alloc.c:4192 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501 alloc_slab_page mm/slub.c:1780 [inline] allocate_slab mm/slub.c:1917 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1980 ___slab_alloc+0x807/0xdd0 mm/slub.c:3013 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc+0xf0/0x280 mm/slub.c:3238 mempool_alloc+0x19d/0x510 mm/mempool.c:393 alloc_metapage fs/jfs/jfs_metapage.c:175 [inline] __get_metapage+0x5e8/0x1060 fs/jfs/jfs_metapage.c:652 diReadSpecial+0x24b/0x710 fs/jfs/jfs_imap.c:447 jfs_mount+0x6f/0x860 fs/jfs/jfs_mount.c:87 jfs_fill_super+0x4d6/0xad0 fs/jfs/super.c:561 mount_bdev+0x28a/0x3c0 fs/super.c:1400 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x247/0xa40 fs/namespace.c:3034 do_mount fs/namespace.c:3377 [inline] __do_sys_mount fs/namespace.c:3585 [inline] __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317 free_unref_page_list+0x119/0x830 mm/page_alloc.c:3433 release_pages+0x185f/0x1bd0 mm/swap.c:963 tlb_batch_pages_flush mm/mmu_gather.c:50 [inline] tlb_flush_mmu_free mm/mmu_gather.c:241 [inline] tlb_flush_mmu mm/mmu_gather.c:248 [inline] tlb_finish_mmu+0x1b4/0x370 mm/mmu_gather.c:371 unmap_region+0x344/0x3b0 mm/mmap.c:2669 __do_munmap+0xa29/0xe10 mm/mmap.c:2899 __vm_munmap+0x13f/0x240 mm/mmap.c:2952 __do_sys_munmap mm/mmap.c:2978 [inline] __se_sys_munmap mm/mmap.c:2974 [inline] __x64_sys_munmap+0x67/0x70 mm/mmap.c:2974 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Memory state around the buggy address: ffff8880742cea80: fc fc fc fc fc 00 00 00 00 00 00 00 00 00 00 00 ffff8880742ceb00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc >ffff8880742ceb80: fc fc fc fc fa fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880742cec00: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc ffff8880742cec80: fc fc fc 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================