================================================================== BUG: KASAN: slab-out-of-bounds in afs_split_string fs/afs/addr_prefs.c:51 [inline] BUG: KASAN: slab-out-of-bounds in afs_proc_addr_prefs_write+0x13a9/0x15f0 fs/afs/addr_prefs.c:415 Read of size 1 at addr ffff888021299d47 by task syz.8.4941/30505 CPU: 0 UID: 0 PID: 30505 Comm: syz.8.4941 Tainted: G U 6.15.0-rc5-syzkaller-00038-g707df3375124 #0 PREEMPT(full) Tainted: [U]=USER Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xc3/0x670 mm/kasan/report.c:521 kasan_report+0xe0/0x110 mm/kasan/report.c:634 afs_split_string fs/afs/addr_prefs.c:51 [inline] afs_proc_addr_prefs_write+0x13a9/0x15f0 fs/afs/addr_prefs.c:415 proc_simple_write+0x114/0x1b0 fs/proc/generic.c:825 pde_write fs/proc/inode.c:330 [inline] proc_reg_write+0x23d/0x330 fs/proc/inode.c:342 do_loop_readv_writev fs/read_write.c:848 [inline] do_loop_readv_writev fs/read_write.c:833 [inline] vfs_writev+0x6c4/0xdc0 fs/read_write.c:1057 do_writev+0x132/0x330 fs/read_write.c:1101 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0d5fd8e969 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:00007f0d60ba8038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007f0d5ffb5fa0 RCX: 00007f0d5fd8e969 RDX: 0000000000000003 RSI: 0000200000000080 RDI: 0000000000000003 RBP: 00007f0d5fe10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f0d5ffb5fa0 R15: 00007ffee099d958 Allocated by task 30505: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4327 [inline] __kmalloc_node_track_caller_noprof+0x221/0x510 mm/slub.c:4346 memdup_user_nul+0x2b/0x120 mm/util.c:302 proc_simple_write+0xc7/0x1b0 fs/proc/generic.c:822 pde_write fs/proc/inode.c:330 [inline] proc_reg_write+0x23d/0x330 fs/proc/inode.c:342 do_loop_readv_writev fs/read_write.c:848 [inline] do_loop_readv_writev fs/read_write.c:833 [inline] vfs_writev+0x6c4/0xdc0 fs/read_write.c:1057 do_writev+0x132/0x330 fs/read_write.c:1101 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888021299d40 which belongs to the cache kmalloc-8 of size 8 The buggy address is located 0 bytes to the right of allocated 7-byte region [ffff888021299d40, ffff888021299d47) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x21299 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801b441500 dead000000000100 dead000000000122 raw: 0000000000000000 0000000080800080 00000000f5000000 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1, tgid 1 (swapper/0), ts 3308631125, free_ts 3194717643 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1718 prep_new_page mm/page_alloc.c:1726 [inline] get_page_from_freelist+0x135c/0x3920 mm/page_alloc.c:3688 __alloc_frozen_pages_noprof+0x263/0x23a0 mm/page_alloc.c:4970 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2301 alloc_slab_page mm/slub.c:2450 [inline] allocate_slab mm/slub.c:2618 [inline] new_slab+0x244/0x340 mm/slub.c:2672 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3858 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3948 __slab_alloc_node mm/slub.c:4023 [inline] slab_alloc_node mm/slub.c:4184 [inline] __do_kmalloc_node mm/slub.c:4326 [inline] __kmalloc_noprof+0x2f2/0x510 mm/slub.c:4339 kmalloc_noprof include/linux/slab.h:909 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] acpi_ns_internalize_name+0x144/0x220 drivers/acpi/acpica/nsutils.c:331 acpi_ns_get_node_unlocked+0x163/0x310 drivers/acpi/acpica/nsutils.c:666 acpi_ns_get_node+0x4c/0x70 drivers/acpi/acpica/nsutils.c:726 acpi_get_handle+0x105/0x270 drivers/acpi/acpica/nsxfname.c:98 acpi_has_method+0x7a/0xc0 drivers/acpi/utils.c:672 is_ejectable_bay drivers/acpi/scan.c:1257 [inline] acpi_scan_init_hotplug drivers/acpi/scan.c:2056 [inline] acpi_bus_check_add+0x2d6/0x910 drivers/acpi/scan.c:2177 acpi_ns_walk_namespace+0x405/0x5b0 drivers/acpi/acpica/nswalk.c:233 acpi_walk_namespace drivers/acpi/acpica/nsxfeval.c:606 [inline] acpi_walk_namespace+0x110/0x130 drivers/acpi/acpica/nsxfeval.c:554 page last free pid 1 tgid 1 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1262 [inline] __free_frozen_pages+0x69d/0xff0 mm/page_alloc.c:2725 discard_slab mm/slub.c:2716 [inline] __put_partials+0x16d/0x1c0 mm/slub.c:3185 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4e/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_remove_cache+0xe7/0x180 mm/kasan/quarantine.c:364 kmem_cache_shrink+0xd/0x20 mm/slab_common.c:558 acpi_os_purge_cache+0x15/0x20 drivers/acpi/osl.c:1605 acpi_purge_cached_objects+0x86/0x100 drivers/acpi/acpica/utxface.c:239 acpi_initialize_objects+0x47/0xa0 drivers/acpi/acpica/utxfinit.c:250 acpi_bus_init drivers/acpi/bus.c:1367 [inline] acpi_init+0x168/0xb80 drivers/acpi/bus.c:1454 do_one_initcall+0x120/0x6e0 init/main.c:1257 do_initcall_level init/main.c:1319 [inline] do_initcalls init/main.c:1335 [inline] do_basic_setup init/main.c:1354 [inline] kernel_init_freeable+0x5c2/0x900 init/main.c:1567 kernel_init+0x1c/0x2b0 init/main.c:1457 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff888021299c00: fa fc fc fc fa fc fc fc 05 fc fc fc 07 fc fc fc ffff888021299c80: 05 fc fc fc fa fc fc fc fa fc fc fc fa fc fc fc >ffff888021299d00: 00 fc fc fc 05 fc fc fc 07 fc fc fc 00 fc fc fc ^ ffff888021299d80: 05 fc fc fc fa fc fc fc 05 fc fc fc fa fc fc fc ffff888021299e00: 00 fc fc fc 05 fc fc fc fa fc fc fc 03 fc fc fc ==================================================================