Buffer I/O error on dev loop4, logical block 3245768, async page read ================================================================== BUG: KASAN: use-after-free in sysv_new_inode+0x1062/0x11f0 fs/sysv/ialloc.c:153 Read of size 2 at addr ffff88805c5fb1ce by task syz.4.1189/8397 CPU: 0 PID: 8397 Comm: syz.4.1189 Not tainted 5.15.172-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 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_inode+0x1062/0x11f0 fs/sysv/ialloc.c:153 sysv_symlink+0x9b/0x180 fs/sysv/namei.c:80 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: 0033:0x7fb238d11719 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:00007fb237189038 EFLAGS: 00000246 ORIG_RAX: 0000000000000058 RAX: ffffffffffffffda RBX: 00007fb238ec8f80 RCX: 00007fb238d11719 RDX: 0000000000000000 RSI: 00000000200059c0 RDI: 0000000020002840 RBP: 00007fb238d8475e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fb238ec8f80 R15: 00007ffcc8583598 The buggy address belongs to the page: page:ffffea0001717ec0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x5c5fb flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 ffffea0001710508 ffffea0001717e88 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 8180, ts 124478901083, free_ts 126094479842 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:5464 alloc_pages_vma+0x39a/0x800 mm/mempolicy.c:2146 shmem_alloc_page mm/shmem.c:1588 [inline] shmem_alloc_and_acct_page+0x4d1/0xd10 mm/shmem.c:1613 shmem_getpage_gfp+0x17b1/0x3190 mm/shmem.c:1908 shmem_getpage mm/shmem.c:151 [inline] shmem_write_begin+0xce/0x1a0 mm/shmem.c:2479 generic_perform_write+0x2bf/0x5b0 mm/filemap.c:3785 __generic_file_write_iter+0x243/0x4f0 mm/filemap.c:3912 generic_file_write_iter+0xa7/0x1b0 mm/filemap.c:3944 call_write_iter include/linux/fs.h:2174 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0xacd/0xe50 fs/read_write.c:594 ksys_write+0x1a2/0x2c0 fs/read_write.c:647 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:1147 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 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x106/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86 Memory state around the buggy address: ffff88805c5fb080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88805c5fb100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88805c5fb180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88805c5fb200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88805c5fb280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================