BTRFS info (device loop0): clearing compat-ro feature flag for FREE_SPACE_TREE (0x1) BTRFS info (device loop0): clearing compat-ro feature flag for FREE_SPACE_TREE_VALID (0x2) ================================================================== BUG: KASAN: null-ptr-deref in instrument_atomic_read_write include/linux/instrumented.h:101 [inline] BUG: KASAN: null-ptr-deref in atomic_inc_not_zero include/linux/atomic/atomic-instrumented.h:577 [inline] BUG: KASAN: null-ptr-deref in btrfs_root_node+0x14c/0x3d4 fs/btrfs/ctree.c:140 Write of size 4 at addr 0000000000000060 by task syz.0.15/4860 CPU: 0 PID: 4860 Comm: syz.0.15 Not tainted 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 __kasan_report mm/kasan/report.c:438 [inline] kasan_report+0xe0/0x15c mm/kasan/report.c:451 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x270/0x2b0 mm/kasan/generic.c:189 __kasan_check_write+0x44/0x54 mm/kasan/shadow.c:37 instrument_atomic_read_write include/linux/instrumented.h:101 [inline] atomic_inc_not_zero include/linux/atomic/atomic-instrumented.h:577 [inline] btrfs_root_node+0x14c/0x3d4 fs/btrfs/ctree.c:140 btrfs_read_lock_root_node+0x68/0x35c fs/btrfs/locking.c:276 btrfs_search_slot_get_root fs/btrfs/ctree.c:1654 [inline] btrfs_search_slot+0x2fc/0x1f4c fs/btrfs/ctree.c:1818 btrfs_orphan_cleanup+0x17c/0x7e0 fs/btrfs/inode.c:3541 btrfs_cleanup_fs_roots+0x520/0x7a8 fs/btrfs/disk-io.c:4305 btrfs_start_pre_rw_mount+0x14c/0x568 fs/btrfs/disk-io.c:3102 open_ctree+0x1ef0/0x27b8 fs/btrfs/disk-io.c:3634 btrfs_fill_super+0x1b4/0x2d4 fs/btrfs/super.c:1387 btrfs_mount_root+0x730/0x780 fs/btrfs/super.c:1751 legacy_get_tree+0xd4/0x16c fs/fs_context.c:611 vfs_get_tree+0x90/0x274 fs/super.c:1530 fc_mount fs/namespace.c:1000 [inline] vfs_kern_mount+0xdc/0x178 fs/namespace.c:1030 btrfs_mount+0x2a0/0x8d4 fs/btrfs/super.c:1811 legacy_get_tree+0xd4/0x16c fs/fs_context.c:611 vfs_get_tree+0x90/0x274 fs/super.c:1530 do_new_mount+0x228/0x810 fs/namespace.c:3013 path_mount+0x5b4/0x1000 fs/namespace.c:3343 do_mount fs/namespace.c:3356 [inline] __do_sys_mount fs/namespace.c:3564 [inline] __se_sys_mount fs/namespace.c:3541 [inline] __arm64_sys_mount+0x514/0x5e4 fs/namespace.c:3541 __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 ================================================================== Unable to handle kernel paging request at virtual address dfff80000000000c Mem abort info: ESR = 0x0000000096000006 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x06: level 2 translation fault Data abort info: ISV = 0, ISS = 0x00000006 CM = 0, WnR = 0 [dfff80000000000c] address between user and kernel address ranges Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 4860 Comm: syz.0.15 Tainted: G B 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 : arch_atomic_fetch_add_unless include/linux/atomic/atomic-arch-fallback.h:1172 [inline] pc : arch_atomic_add_unless include/linux/atomic/atomic-arch-fallback.h:1197 [inline] pc : arch_atomic_inc_not_zero include/linux/atomic/atomic-arch-fallback.h:1213 [inline] pc : atomic_inc_not_zero include/linux/atomic/atomic-instrumented.h:578 [inline] pc : btrfs_root_node+0x150/0x3d4 fs/btrfs/ctree.c:140 lr : instrument_atomic_read_write include/linux/instrumented.h:101 [inline] lr : atomic_inc_not_zero include/linux/atomic/atomic-instrumented.h:577 [inline] lr : btrfs_root_node+0x14c/0x3d4 fs/btrfs/ctree.c:140 sp : ffff80001f406f90 x29: ffff80001f406f90 x28: dfff800000000000 x27: ffff8000116c1e40 x26: 0000000000000060 x25: 0000000000000000 x24: ffff8000116c1e40 x23: ffff80001658d000 x22: ffff8000116c25c0 x21: 0000000000000001 x20: 1fffe0001aecd000 x19: ffff0000d7668000 x18: 0000000000000002 x17: 0000000040000000 x16: ffff8000082d4b24 x15: 0000000000000002 x14: 0000000000ff0100 x13: ffffffffffffffff x12: 0000000000ff0100 x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000 x8 : 000000000000000c x7 : 0000000000000000 x6 : ffff800008244078 x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff800008184528 x2 : 0000000000000001 x1 : 0000000000000001 x0 : 0000000000000000 Call trace: arch_atomic_fetch_add_unless include/linux/atomic/atomic-arch-fallback.h:1172 [inline] arch_atomic_add_unless include/linux/atomic/atomic-arch-fallback.h:1197 [inline] arch_atomic_inc_not_zero include/linux/atomic/atomic-arch-fallback.h:1213 [inline] atomic_inc_not_zero include/linux/atomic/atomic-instrumented.h:578 [inline] btrfs_root_node+0x150/0x3d4 fs/btrfs/ctree.c:140 btrfs_read_lock_root_node+0x68/0x35c fs/btrfs/locking.c:276 btrfs_search_slot_get_root fs/btrfs/ctree.c:1654 [inline] btrfs_search_slot+0x2fc/0x1f4c fs/btrfs/ctree.c:1818 btrfs_orphan_cleanup+0x17c/0x7e0 fs/btrfs/inode.c:3541 btrfs_cleanup_fs_roots+0x520/0x7a8 fs/btrfs/disk-io.c:4305 btrfs_start_pre_rw_mount+0x14c/0x568 fs/btrfs/disk-io.c:3102 open_ctree+0x1ef0/0x27b8 fs/btrfs/disk-io.c:3634 btrfs_fill_super+0x1b4/0x2d4 fs/btrfs/super.c:1387 btrfs_mount_root+0x730/0x780 fs/btrfs/super.c:1751 legacy_get_tree+0xd4/0x16c fs/fs_context.c:611 vfs_get_tree+0x90/0x274 fs/super.c:1530 fc_mount fs/namespace.c:1000 [inline] vfs_kern_mount+0xdc/0x178 fs/namespace.c:1030 btrfs_mount+0x2a0/0x8d4 fs/btrfs/super.c:1811 legacy_get_tree+0xd4/0x16c fs/fs_context.c:611 vfs_get_tree+0x90/0x274 fs/super.c:1530 do_new_mount+0x228/0x810 fs/namespace.c:3013 path_mount+0x5b4/0x1000 fs/namespace.c:3343 do_mount fs/namespace.c:3356 [inline] __do_sys_mount fs/namespace.c:3564 [inline] __se_sys_mount fs/namespace.c:3541 [inline] __arm64_sys_mount+0x514/0x5e4 fs/namespace.c:3541 __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 Code: aa1b03f8 aa1a03e0 97a91345 d343ff48 (38fc6908) ---[ end trace 2e0c938ab23d270e ]--- ---------------- Code disassembly (best guess): 0: aa1b03f8 mov x24, x27 4: aa1a03e0 mov x0, x26 8: 97a91345 bl 0xfffffffffea44d1c c: d343ff48 lsr x8, x26, #3 * 10: 38fc6908 ldrsb w8, [x8, x28] <-- trapping instruction