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 ffff888072e430c8 by task syz.1.102/4796 CPU: 1 PID: 4796 Comm: syz.1.102 Not tainted 5.15.178-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: 0033:0x7fd23da49de9 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:00007fd23b871038 EFLAGS: 00000246 ORIG_RAX: 0000000000000058 RAX: ffffffffffffffda RBX: 00007fd23dc63160 RCX: 00007fd23da49de9 RDX: 0000000000000000 RSI: 000040000000acc0 RDI: 000040000000ad80 RBP: 00007fd23dacb2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fd23dc63160 R15: 00007fffc715a638 The buggy address belongs to the page: page:ffffea0001cb90c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x100 pfn:0x72e43 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 dead000000000100 dead000000000122 0000000000000000 raw: 0000000000000100 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 0x1100dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), pid 4748, ts 94690791259, free_ts 96061838986 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 wp_page_copy+0x221/0x2070 mm/memory.c:3049 handle_pte_fault mm/memory.c:4666 [inline] __handle_mm_fault mm/memory.c:4783 [inline] handle_mm_fault+0x2a3d/0x5960 mm/memory.c:4881 do_user_addr_fault arch/x86/mm/fault.c:1357 [inline] handle_page_fault arch/x86/mm/fault.c:1445 [inline] exc_page_fault+0x271/0x700 arch/x86/mm/fault.c:1501 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 __put_user_nocheck_4+0x3/0x11 ____sys_recvmsg+0x35b/0x530 net/socket.c:2668 ___sys_recvmsg+0x1ec/0x690 net/socket.c:2697 do_recvmmsg+0x36f/0x8f0 net/socket.c:2791 __sys_recvmmsg net/socket.c:2870 [inline] __do_sys_recvmmsg net/socket.c:2893 [inline] __se_sys_recvmmsg net/socket.c:2886 [inline] __x64_sys_recvmmsg+0x195/0x240 net/socket.c:2886 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 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline] tlb_flush_mmu_free mm/mmu_gather.c:240 [inline] tlb_flush_mmu+0xc8/0x170 mm/mmu_gather.c:247 zap_pte_range mm/memory.c:1456 [inline] zap_pmd_range mm/memory.c:1505 [inline] zap_pud_range mm/memory.c:1534 [inline] zap_p4d_range mm/memory.c:1555 [inline] unmap_page_range+0x214d/0x2630 mm/memory.c:1576 unmap_vmas+0x1f8/0x390 mm/memory.c:1653 exit_mmap+0x3b6/0x620 mm/mmap.c:3204 __mmput+0x112/0x3b0 kernel/fork.c:1127 exit_mm+0x688/0x7f0 kernel/exit.c:550 do_exit+0x626/0x2480 kernel/exit.c:861 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 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:178 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 Memory state around the buggy address: ffff888072e42f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888072e43000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff888072e43080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff888072e43100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888072e43180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================