================================================================== BUG: KASAN: slab-out-of-bounds in scr_memcpyw include/linux/vt_buffer.h:38 [inline] BUG: KASAN: slab-out-of-bounds in fbcon_prepare_logo+0xa03/0xc70 drivers/video/fbdev/core/fbcon.c:613 Read of size 6 at addr ffff88803083d4b6 by task syz.1.1234/11723 CPU: 1 UID: 0 PID: 11723 Comm: syz.1.1234 Tainted: G U 6.15.0-rc6-syzkaller-00085-gc94d59a126cb #0 PREEMPT(full) Tainted: [U]=USER Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189 __asan_memcpy+0x23/0x60 mm/kasan/shadow.c:105 scr_memcpyw include/linux/vt_buffer.h:38 [inline] fbcon_prepare_logo+0xa03/0xc70 drivers/video/fbdev/core/fbcon.c:613 fbcon_init+0xd77/0x1900 drivers/video/fbdev/core/fbcon.c:1145 visual_init+0x31d/0x620 drivers/tty/vt/vt.c:1011 do_bind_con_driver.isra.0+0x57a/0xbf0 drivers/tty/vt/vt.c:3831 vt_bind drivers/tty/vt/vt.c:3987 [inline] store_bind+0x61d/0x760 drivers/tty/vt/vt.c:4059 dev_attr_store+0x58/0x80 drivers/base/core.c:2440 sysfs_kf_write+0xef/0x150 fs/sysfs/file.c:145 kernfs_fop_write_iter+0x354/0x510 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:591 [inline] vfs_write+0x5bd/0x1180 fs/read_write.c:684 ksys_write+0x12a/0x240 fs/read_write.c:736 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: 0033:0x7f71ec98e969 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:00007f71ed76d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f71ecbb5fa0 RCX: 00007f71ec98e969 RDX: 00000000fffffdef RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007f71eca10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f71ecbb5fa0 R15: 00007fff322a5478 Allocated by task 11726: 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 kmemdup_noprof+0x29/0x60 mm/util.c:137 kmemdup_noprof include/linux/fortify-string.h:765 [inline] shmem_symlink+0x257/0x970 mm/shmem.c:4110 vfs_symlink fs/namei.c:4723 [inline] vfs_symlink+0x400/0x680 fs/namei.c:4707 do_symlinkat+0x261/0x310 fs/namei.c:4749 __do_sys_symlinkat fs/namei.c:4765 [inline] __se_sys_symlinkat fs/namei.c:4762 [inline] __x64_sys_symlinkat+0x93/0xc0 fs/namei.c:4762 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 ffff88803083d480 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 30 bytes to the right of allocated 24-byte region [ffff88803083d480, ffff88803083d498) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3083d anon flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801b441780 0000000000000000 dead000000000001 raw: 0000000000000000 0000000000400040 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 0x52800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP), pid 5770, tgid 5770 (dhcpcd-run-hook), ts 83809211869, free_ts 83806988529 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] __kmalloc_cache_noprof+0xfb/0x3e0 mm/slub.c:4353 kmalloc_noprof include/linux/slab.h:905 [inline] slab_free_hook mm/slub.c:2332 [inline] slab_free mm/slub.c:4642 [inline] kmem_cache_free+0x148/0x4d0 mm/slub.c:4744 exit_mmap+0x511/0xb90 mm/mmap.c:1309 __mmput+0x12a/0x410 kernel/fork.c:1379 mmput+0x62/0x70 kernel/fork.c:1401 exec_mmap fs/exec.c:1009 [inline] begin_new_exec+0x15a7/0x38b0 fs/exec.c:1264 load_elf_binary+0x88c/0x4eb0 fs/binfmt_elf.c:1002 search_binary_handler fs/exec.c:1778 [inline] exec_binprm fs/exec.c:1810 [inline] bprm_execve fs/exec.c:1862 [inline] bprm_execve+0x8c3/0x1650 fs/exec.c:1838 do_execveat_common.isra.0+0x4a5/0x610 fs/exec.c:1968 page last free pid 5770 tgid 5770 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 tlb_batch_list_free mm/mmu_gather.c:159 [inline] tlb_finish_mmu+0x237/0x7b0 mm/mmu_gather.c:499 exit_mmap+0x403/0xb90 mm/mmap.c:1297 __mmput+0x12a/0x410 kernel/fork.c:1379 mmput+0x62/0x70 kernel/fork.c:1401 exec_mmap fs/exec.c:1009 [inline] begin_new_exec+0x15a7/0x38b0 fs/exec.c:1264 load_elf_binary+0x88c/0x4eb0 fs/binfmt_elf.c:1002 search_binary_handler fs/exec.c:1778 [inline] exec_binprm fs/exec.c:1810 [inline] bprm_execve fs/exec.c:1862 [inline] bprm_execve+0x8c3/0x1650 fs/exec.c:1838 do_execveat_common.isra.0+0x4a5/0x610 fs/exec.c:1968 do_execve fs/exec.c:2042 [inline] __do_sys_execve fs/exec.c:2118 [inline] __se_sys_execve fs/exec.c:2113 [inline] __x64_sys_execve+0x8e/0xb0 fs/exec.c:2113 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 Memory state around the buggy address: ffff88803083d380: fa fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc ffff88803083d400: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc >ffff88803083d480: 00 00 00 fc fc fc fc fc 00 00 00 06 fc fc fc fc ^ ffff88803083d500: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ffff88803083d580: 00 00 00 fc fc fc fc fc fa fb fb fb fc fc fc fc ==================================================================