------------[ cut here ]------------ WARNING: CPU: 1 PID: 6011 at fs/inode.c:389 inc_nlink+0x130/0x168 fs/inode.c:389 Modules linked in: CPU: 1 PID: 6011 Comm: syz.2.315 Not tainted 5.15.182-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : inc_nlink+0x130/0x168 fs/inode.c:389 lr : inc_nlink+0x130/0x168 fs/inode.c:389 sp : ffff800020617b90 x29: ffff800020617b90 x28: dfff800000000000 x27: 0000000000000000 x26: 1fffe0001bc9d80c x25: ffff80001155cf48 x24: 00000000000001c0 x23: 1fffe0001bc9d810 x22: dfff800000000000 x21: 0000000000000000 x20: ffff0000de4ec038 x19: ffff0000de4ec080 x18: 0000000000000000 x17: 0000000000000002 x16: ffff8000111a53fc x15: 0000000000000003 x14: 00000000ffff8000 x13: 000000007356e826 x12: 0000000000080000 x11: 00000000000026b1 x10: ffff8000297a2000 x9 : ffff80000894efe0 x8 : 00000000000026b2 x7 : 0000000000000000 x6 : 000000000000003f x5 : 0000000000000040 x4 : 0000000000000000 x3 : 00000000000001c0 x2 : ffff0000f083aeb0 x1 : 0000000000000000 x0 : 0000000000000000 Call trace: inc_nlink+0x130/0x168 fs/inode.c:389 inode_inc_link_count include/linux/fs.h:2497 [inline] sysv_mkdir+0x2c/0x138 fs/sysv/namei.c:119 vfs_mkdir+0x314/0x4d4 fs/namei.c:4065 do_mkdirat+0x1bc/0x508 fs/namei.c:4090 __do_sys_mkdirat fs/namei.c:4105 [inline] __se_sys_mkdirat fs/namei.c:4103 [inline] __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4103 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 irq event stamp: 4210 hardirqs last enabled at (4209): [] kasan_quarantine_put+0xc4/0x204 mm/kasan/quarantine.c:231 hardirqs last disabled at (4210): [] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:396 softirqs last enabled at (4170): [] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:31 softirqs last disabled at (4168): [] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:18 ---[ end trace dae110ec51fbe919 ]--- ================================================================== BUG: KASAN: use-after-free in sysv_new_block+0x600/0x798 fs/sysv/balloc.c:113 Read of size 4 at addr ffff0000eebb70c8 by task syz.2.315/6011 CPU: 0 PID: 6011 Comm: syz.2.315 Tainted: G W 5.15.182-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 Call trace: dump_backtrace+0x0/0x43c arch/arm64/kernel/stacktrace.c:152 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf8/0x160 lib/dump_stack.c:106 print_address_description+0x78/0x30c mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xec/0x15c mm/kasan/report.c:451 __asan_report_load4_noabort+0x44/0x50 mm/kasan/report_generic.c:308 sysv_new_block+0x600/0x798 fs/sysv/balloc.c:113 alloc_branch fs/sysv/itree.c:134 [inline] get_block+0x208/0x126c fs/sysv/itree.c:253 __block_write_begin_int+0x3e4/0x1588 fs/buffer.c:2012 __block_write_begin+0x40/0x54 fs/buffer.c:2062 sysv_prepare_chunk+0x3c/0x50 fs/sysv/itree.c:468 sysv_make_empty+0x94/0x4f0 fs/sysv/dir.c:257 sysv_mkdir+0x88/0x138 fs/sysv/namei.c:130 vfs_mkdir+0x314/0x4d4 fs/namei.c:4065 do_mkdirat+0x1bc/0x508 fs/namei.c:4090 __do_sys_mkdirat fs/namei.c:4105 [inline] __se_sys_mkdirat fs/namei.c:4103 [inline] __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4103 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 The buggy address belongs to the page: page:000000004429ebf3 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x12ebb7 flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000000000 fffffc0003baee08 fffffc0003baed88 0000000000000000 raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000eebb6f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff0000eebb7000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff0000eebb7080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff0000eebb7100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff0000eebb7180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================