loop4: rw=0, sector=6491536, nr_sectors = 2 limit=128 Buffer I/O error on dev loop4, logical block 3245768, async page read ================================================================== BUG: KASAN: use-after-free in sysv_new_inode+0xd8c/0xf04 fs/sysv/ialloc.c:153 Read of size 2 at addr ffff0000fcfa51ce by task syz.4.292/6238 CPU: 0 PID: 6238 Comm: syz.4.292 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025 Call trace: dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf8/0x160 lib/dump_stack.c:106 print_address_description+0x88/0x218 mm/kasan/report.c:316 print_report+0x50/0x68 mm/kasan/report.c:420 kasan_report+0xa8/0x100 mm/kasan/report.c:524 __asan_report_load2_noabort+0x2c/0x38 mm/kasan/report_generic.c:349 sysv_new_inode+0xd8c/0xf04 fs/sysv/ialloc.c:153 sysv_mknod+0x5c/0x100 fs/sysv/namei.c:53 sysv_create+0x38/0x4c fs/sysv/namei.c:67 lookup_open fs/namei.c:3490 [inline] open_last_lookups fs/namei.c:3558 [inline] path_openat+0x112c/0x2680 fs/namei.c:3788 do_filp_open+0x174/0x344 fs/namei.c:3818 do_sys_openat2+0x128/0x3d8 fs/open.c:1318 do_sys_open fs/open.c:1334 [inline] __do_sys_openat fs/open.c:1350 [inline] __se_sys_openat fs/open.c:1345 [inline] __arm64_sys_openat+0x120/0x154 fs/open.c:1345 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x138 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 The buggy address belongs to the physical page: page:00000000e2b7e31a refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x13cfa5 flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000000000 dead000000000100 dead000000000122 0000000000000000 raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000fcfa5080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff0000fcfa5100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff0000fcfa5180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff0000fcfa5200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff0000fcfa5280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== syz.4.292: attempt to access beyond end of device loop4: rw=0, sector=6491536, nr_sectors = 2 limit=128 Buffer I/O error on dev loop4, logical block 3245768, async page read syz.4.292: attempt to access beyond end of device loop4: rw=0, sector=6491536, nr_sectors = 2 limit=128 Buffer I/O error on dev loop4, logical block 3245768, async page read ------------[ cut here ]------------ WARNING: CPU: 0 PID: 6238 at fs/inode.c:389 inc_nlink+0x128/0x154 fs/inode.c:389 Modules linked in: CPU: 0 PID: 6238 Comm: syz.4.292 Tainted: G B syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025 pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--) pc : inc_nlink+0x128/0x154 fs/inode.c:389 lr : inc_nlink+0x128/0x154 fs/inode.c:389 sp : ffff800021ed7b90 x29: ffff800021ed7b90 x28: dfff800000000000 x27: 0000000000000000 x26: 1fffe0001f83700c x25: ffff800011d44c48 x24: 0000000000000062 x23: 1fffe0001f837010 x22: dfff800000000000 x21: 0000000000000000 x20: ffff0000fc1b8038 x19: ffff0000fc1b8080 x18: ffff800011abbcc0 x17: 1fffe00033ed797e x16: ffff800008042d90 x15: 0000000000000002 x14: 00000000ffff8000 x13: 0000000008b9190c x12: 0000000000080000 x11: 0000000000002bbd x10: ffff80002a976000 x9 : ffff8000089fcc64 x8 : 0000000000002bbe x7 : 0000000000000000 x6 : 000000000000003f x5 : 0000000000000040 x4 : 0000000000000001 x3 : 0000000000000062 x2 : ffff0000f5a17608 x1 : 0000000000000000 x0 : 0000000000000000 Call trace: inc_nlink+0x128/0x154 fs/inode.c:389 inode_inc_link_count include/linux/fs.h:2576 [inline] sysv_mkdir+0x2c/0x138 fs/sysv/namei.c:119 vfs_mkdir+0x314/0x4d4 fs/namei.c:4114 do_mkdirat+0x1b4/0x3e0 fs/namei.c:4139 __do_sys_mkdirat fs/namei.c:4154 [inline] __se_sys_mkdirat fs/namei.c:4152 [inline] __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4152 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x138 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 irq event stamp: 2441 hardirqs last enabled at (2441): [] raw_spin_rq_unlock_irq kernel/sched/sched.h:1367 [inline] hardirqs last enabled at (2441): [] finish_lock_switch+0xb0/0x1c4 kernel/sched/core.c:5003 hardirqs last disabled at (2440): [] __schedule+0x298/0x1b18 kernel/sched/core.c:6459 softirqs last enabled at (2120): [] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32 softirqs last disabled at (2118): [] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19 ---[ end trace 0000000000000000 ]--- netlink: 128 bytes leftover after parsing attributes in process `syz.4.292'. netlink: 16 bytes leftover after parsing attributes in process `syz.4.292'.