attempt to access beyond end of device loop1: rw=0, want=6491538, limit=128 Buffer I/O error on dev loop1, logical block 3245768, async page read ================================================================== BUG: KASAN: use-after-free in sysv_new_block+0x788/0x960 fs/sysv/balloc.c:113 Read of size 4 at addr ffff8880697220c8 by task syz.1.173/5006 CPU: 1 PID: 5006 Comm: syz.1.173 Not tainted 5.15.177-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 print_address_description+0x63/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0x16b/0x1c0 mm/kasan/report.c:451 sysv_new_block+0x788/0x960 fs/sysv/balloc.c:113 alloc_branch fs/sysv/itree.c:134 [inline] get_block+0x2e7/0x1790 fs/sysv/itree.c:253 __block_write_begin_int+0x60b/0x1650 fs/buffer.c:2012 __block_write_begin fs/buffer.c:2062 [inline] block_write_begin+0x4f/0xc0 fs/buffer.c:2122 sysv_write_begin+0x36/0x70 fs/sysv/itree.c:487 __page_symlink+0x15b/0x2a0 fs/namei.c:5177 sysv_symlink+0xcb/0x180 fs/sysv/namei.c:86 vfs_symlink+0x247/0x3d0 fs/namei.c:4429 do_symlinkat+0x1fd/0x600 fs/namei.c:4458 __do_sys_symlink fs/namei.c:4480 [inline] __se_sys_symlink fs/namei.c:4478 [inline] __x64_sys_symlink+0x7a/0x90 fs/namei.c:4478 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f678589dd29 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f6783707038 EFLAGS: 00000246 ORIG_RAX: 0000000000000058 RAX: ffffffffffffffda RBX: 00007f6785ab6fa0 RCX: 00007f678589dd29 RDX: 0000000000000000 RSI: 00000000200059c0 RDI: 0000000020002840 RBP: 00007f678591f2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f6785ab6fa0 R15: 00007fff7c83d4b8 The buggy address belongs to the page: page:ffffea0001a5c880 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x69722 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 ffffea0001a5c8c8 ffffea0001a5c848 0000000000000000 raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 0, migratetype Movable, gfp_mask 0x1100cca(GFP_HIGHUSER_MOVABLE), pid 5019, ts 153074021993, free_ts 153736185987 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x3b78/0x3d40 mm/page_alloc.c:4192 __alloc_pages+0x272/0x700 mm/page_alloc.c:5465 alloc_pages_vma+0x39a/0x800 mm/mempolicy.c:2146 shmem_alloc_page mm/shmem.c:1586 [inline] shmem_alloc_and_acct_page+0x4d1/0xd10 mm/shmem.c:1611 shmem_getpage_gfp+0x17b1/0x3190 mm/shmem.c:1906 shmem_fault+0x1d7/0x700 mm/shmem.c:2118 __do_fault+0x139/0x340 mm/memory.c:3926 do_read_fault mm/memory.c:4262 [inline] do_fault mm/memory.c:4390 [inline] handle_pte_fault mm/memory.c:4648 [inline] __handle_mm_fault mm/memory.c:4783 [inline] handle_mm_fault+0x376f/0x5960 mm/memory.c:4881 faultin_page mm/gup.c:976 [inline] __get_user_pages+0x4ed/0x11d0 mm/gup.c:1197 populate_vma_page_range+0x215/0x2a0 mm/gup.c:1529 __mm_populate+0x2a5/0x4a0 mm/gup.c:1638 mm_populate include/linux/mm.h:2632 [inline] vm_mmap_pgoff+0x22b/0x2d0 mm/util.c:556 ksys_mmap_pgoff+0x13e/0x780 mm/mmap.c:1623 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 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+0xc34/0xcf0 mm/page_alloc.c:3317 free_unref_page_list+0x1f7/0x8e0 mm/page_alloc.c:3433 release_pages+0x1bb9/0x1f40 mm/swap.c:963 __pagevec_release+0x80/0xf0 mm/swap.c:983 pagevec_release include/linux/pagevec.h:81 [inline] shmem_undo_range+0x67a/0x1b50 mm/shmem.c:964 shmem_truncate_range mm/shmem.c:1063 [inline] shmem_evict_inode+0x21b/0xa00 mm/shmem.c:1145 evict+0x529/0x930 fs/inode.c:622 __dentry_kill+0x436/0x650 fs/dcache.c:586 dentry_kill+0xbb/0x290 dput+0xd8/0x1a0 fs/dcache.c:893 __fput+0x636/0x8e0 fs/file_table.c:288 task_work_run+0x129/0x1a0 kernel/task_work.c:188 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0x6a3/0x2480 kernel/exit.c:874 do_group_exit+0x144/0x310 kernel/exit.c:996 get_signal+0xc66/0x14e0 kernel/signal.c:2900 arch_do_signal_or_restart+0xc3/0x1890 arch/x86/kernel/signal.c:867 Memory state around the buggy address: ffff888069721f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888069722000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff888069722080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff888069722100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888069722180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================