================================================================== BUG: KASAN: use-after-free in jfs_readdir+0x129f/0x3cf0 fs/jfs/jfs_dtree.c:3179 Read of size 8 at addr ffff888078100030 by task syz-executor/4987 CPU: 1 PID: 4987 Comm: syz-executor 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+0x129f/0x3cf0 fs/jfs/jfs_dtree.c:3179 iterate_dir+0x218/0x560 fs/readdir.c:-1 __do_sys_getdents64 fs/readdir.c:369 [inline] __se_sys_getdents64+0xf2/0x270 fs/readdir.c:354 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: 0033:0x7fee4e56d8b3 Code: c7 c0 e8 ff ff ff 64 c7 00 16 00 00 00 31 c0 eb 9e e8 81 9b fd ff 90 b8 ff ff ff 7f 48 39 c2 48 0f 47 d0 b8 d9 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 c7 c2 e8 ff ff ff f7 d8 RSP: 002b:00007ffea9cec3c8 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 000055555fd85a50 RCX: 00007fee4e56d8b3 RDX: 0000000000008000 RSI: 000055555fd85a80 RDI: 0000000000000005 RBP: 000055555fd85a80 R08: 00000000000285c1 R09: 0000000000000001 R10: 00007fee4e77dcc0 R11: 0000000000000293 R12: 000055555fd85a54 R13: ffffffffffffffe8 R14: 0000000000000010 R15: 00007ffea9cee670 Allocated by task 4987: 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+0x9c/0xd0 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+0x100/0x290 mm/slub.c:3238 mempool_alloc+0x18d/0x4e0 mm/mempool.c:393 alloc_metapage fs/jfs/jfs_metapage.c:175 [inline] __get_metapage+0x5e8/0x1060 fs/jfs/jfs_metapage.c:652 dtReadFirst+0xd5/0x8f0 fs/jfs/jfs_dtree.c:3377 dtReadNext fs/jfs/jfs_dtree.c:3458 [inline] jfs_readdir+0x97e/0x3cf0 fs/jfs/jfs_dtree.c:3172 iterate_dir+0x218/0x560 fs/readdir.c:-1 __do_sys_getdents64 fs/readdir.c:369 [inline] __se_sys_getdents64+0xf2/0x270 fs/readdir.c:354 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 4987: 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+0xea/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+0x97b/0xe10 fs/jfs/jfs_metapage.c:758 dtReadNext fs/jfs/jfs_dtree.c:3500 [inline] jfs_readdir+0x103b/0x3cf0 fs/jfs/jfs_dtree.c:3172 iterate_dir+0x218/0x560 fs/readdir.c:-1 __do_sys_getdents64 fs/readdir.c:369 [inline] __se_sys_getdents64+0xf2/0x270 fs/readdir.c:354 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 ffff888078100000 which belongs to the cache jfs_mp of size 184 The buggy address is located 48 bytes inside of 184-byte region [ffff888078100000, ffff8880781000b8) The buggy address belongs to the page: page:ffffea0001e04000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x78100 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 0000000000000000 dead000000000122 ffff8881469718c0 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 4987, ts 120938628436, free_ts 120912830041 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1bbd/0x1ca0 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+0x80a/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+0x195/0x290 mm/slub.c:3238 mempool_alloc+0x18d/0x4e0 mm/mempool.c:393 alloc_metapage fs/jfs/jfs_metapage.c:175 [inline] __get_metapage+0x5e8/0x1060 fs/jfs/jfs_metapage.c:652 dtReadFirst+0xd5/0x8f0 fs/jfs/jfs_dtree.c:3377 dtReadNext fs/jfs/jfs_dtree.c:3458 [inline] jfs_readdir+0x97e/0x3cf0 fs/jfs/jfs_dtree.c:3172 iterate_dir+0x218/0x560 fs/readdir.c:-1 __do_sys_getdents64 fs/readdir.c:369 [inline] __se_sys_getdents64+0xf2/0x270 fs/readdir.c:354 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 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+0x8f/0x2a0 mm/page_alloc.c:3396 tlb_batch_list_free mm/mmu_gather.c:62 [inline] tlb_finish_mmu+0x28b/0x370 mm/mmu_gather.c:374 unmap_region+0x344/0x3b0 mm/mmap.c:2669 __do_munmap+0x9f8/0xdf0 mm/mmap.c:2899 __vm_munmap+0x140/0x240 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: ffff8880780fff00: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc ffff8880780fff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888078100000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888078100080: fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc ffff888078100100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================