syz.0.78: attempt to access beyond end of device loop0: rw=0, sector=6491536, nr_sectors = 2 limit=128 Buffer I/O error on dev loop0, logical block 3245768, async page read ------------[ cut here ]------------ WARNING: CPU: 1 PID: 4784 at fs/inode.c:389 inc_nlink+0x128/0x154 fs/inode.c:389 Modules linked in: CPU: 1 PID: 4784 Comm: syz.0.78 Not tainted 6.1.119-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 pstate: 80400005 (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 : ffff8000216b7b70 x29: ffff8000216b7b70 x28: dfff800000000000 x27: 0000000000000000 x26: 1fffe0001acd8815 x25: ffff800012704648 x24: 0000000000000000 x23: 1fffe0001c39f010 x22: dfff800000000000 x21: 0000000000000000 x20: ffff0000e1cf8038 x19: ffff0000e1cf8080 x18: ffff8000216b73c0 x17: ffff800018b6a000 x16: ffff80001232421c x15: 0000000000000002 x14: 00000000ffff8000 x13: 000000000dd87992 x12: 0000000000080000 x11: 000000000000d551 x10: ffff800021af9000 x9 : ffff800008aab4f0 x8 : 000000000000d552 x7 : 0000000000000000 x6 : 000000000000003f x5 : 0000000000000040 x4 : 0000000000000001 x3 : 0000000000000000 x2 : ffff0000de4f7028 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+0x334/0x4e4 fs/namei.c:4106 do_mkdirat+0x220/0x510 fs/namei.c:4131 __do_sys_mkdirat fs/namei.c:4146 [inline] __se_sys_mkdirat fs/namei.c:4144 [inline] __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4144 __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+0x58/0x168 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: 141334 hardirqs last enabled at (141333): [] kasan_quarantine_put+0xdc/0x204 mm/kasan/quarantine.c:242 hardirqs last disabled at (141334): [] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405 softirqs last enabled at (141326): [] softirq_handle_end kernel/softirq.c:414 [inline] softirqs last enabled at (141326): [] handle_softirqs+0xb84/0xd58 kernel/softirq.c:599 softirqs last disabled at (141313): [] __do_softirq+0x14/0x20 kernel/softirq.c:605 ---[ end trace 0000000000000000 ]--- ================================================================== BUG: KASAN: use-after-free in sysv_new_block+0x618/0x7e4 fs/sysv/balloc.c:113 Read of size 4 at addr ffff0000fb7cb0c8 by task syz.0.78/4784 CPU: 1 PID: 4784 Comm: syz.0.78 Tainted: G W 6.1.119-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call trace: dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x174/0x4c0 mm/kasan/report.c:395 kasan_report+0xd4/0x130 mm/kasan/report.c:495 __asan_report_load4_noabort+0x2c/0x38 mm/kasan/report_generic.c:350 sysv_new_block+0x618/0x7e4 fs/sysv/balloc.c:113 alloc_branch fs/sysv/itree.c:134 [inline] get_block+0x254/0x1360 fs/sysv/itree.c:253 __block_write_begin_int+0x340/0x13b4 fs/buffer.c:1991 __block_write_begin+0x7c/0xa0 fs/buffer.c:2041 sysv_prepare_chunk+0x3c/0x50 fs/sysv/itree.c:468 sysv_make_empty+0x98/0x500 fs/sysv/dir.c:257 sysv_mkdir+0x88/0x138 fs/sysv/namei.c:130 vfs_mkdir+0x334/0x4e4 fs/namei.c:4106 do_mkdirat+0x220/0x510 fs/namei.c:4131 __do_sys_mkdirat fs/namei.c:4146 [inline] __se_sys_mkdirat fs/namei.c:4144 [inline] __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4144 __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+0x58/0x168 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:0000000078ba903e refcount:2 mapcount:1 mapping:0000000053b0401b index:0x38a pfn:0x13b7cb memcg:ffff0000d23d8000 aops:shmem_aops ino:2e dentry name:"dev/zero" flags: 0x5ffe00000080816(referenced|uptodate|lru|arch_1|swapbacked|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffe00000080816 fffffc0003edf288 fffffc0003edf308 ffff0000f96789b8 raw: 000000000000038a 0000000000000000 0000000200000000 ffff0000d23d8000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000fb7caf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff0000fb7cb000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff0000fb7cb080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ ffff0000fb7cb100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff0000fb7cb180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================