================================================================== 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 ffff88814cdf3da7 by task syz.0.440/8076 CPU: 1 UID: 135 PID: 8076 Comm: syz.0.440 Not tainted 6.15.0-rc4-syzkaller-00052-g4f79eaa2ceac #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 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: 0033:0x7ffa9618e969 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:00007ffa9703e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007ffa963b6240 RCX: 00007ffa9618e969 RDX: 0000000000000003 RSI: 0000200000000080 RDI: 0000000000000009 RBP: 00007ffa96210ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ffa963b6240 R15: 00007ffd736e0238 Allocated by task 8076: 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:4341 [inline] __kmalloc_node_track_caller_noprof+0x221/0x510 mm/slub.c:4360 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 ffff88814cdf3da0 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 [ffff88814cdf3da0, ffff88814cdf3da7) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x14cdf3 flags: 0x57ff00000000000(node=1|zone=2|lastcpupid=0x7ff) page_type: f5(slab) raw: 057ff00000000000 ffff88801b441500 ffffea000098e380 dead000000000002 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 31854138561, free_ts 29200753234 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:2468 [inline] allocate_slab mm/slub.c:2632 [inline] new_slab+0x244/0x340 mm/slub.c:2686 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3872 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3962 __slab_alloc_node mm/slub.c:4037 [inline] slab_alloc_node mm/slub.c:4198 [inline] __do_kmalloc_node mm/slub.c:4340 [inline] __kmalloc_node_track_caller_noprof+0x2ee/0x510 mm/slub.c:4360 __kmemdup_nul mm/util.c:63 [inline] kstrdup+0x53/0x100 mm/util.c:83 kstrdup_const+0x63/0x80 mm/util.c:103 kvasprintf_const+0x10f/0x1a0 lib/kasprintf.c:48 kobject_set_name_vargs+0x5a/0x140 lib/kobject.c:274 kobject_add_varg lib/kobject.c:368 [inline] kobject_init_and_add+0xe7/0x190 lib/kobject.c:457 lookup_or_create_module_kobject.part.0+0xbe/0x170 kernel/params.c:779 lookup_or_create_module_kobject kernel/params.c:987 [inline] kernel_add_sysfs_param kernel/params.c:802 [inline] param_sysfs_builtin kernel/params.c:850 [inline] param_sysfs_builtin_init+0x3ec/0x4c0 kernel/params.c:984 do_one_initcall+0x120/0x6e0 init/main.c:1257 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 vfree+0x176/0x960 mm/vmalloc.c:3383 tpg_free+0x72/0x480 drivers/media/common/v4l2-tpg/v4l2-tpg-core.c:193 vivid_dev_release+0xd0/0x160 drivers/media/test-drivers/vivid/vivid-core.c:865 v4l2_device_release drivers/media/v4l2-core/v4l2-device.c:51 [inline] kref_put include/linux/kref.h:65 [inline] v4l2_device_put+0xa0/0xd0 drivers/media/v4l2-core/v4l2-device.c:56 vivid_create_instance drivers/media/test-drivers/vivid/vivid-core.c:2070 [inline] vivid_probe drivers/media/test-drivers/vivid/vivid-core.c:2095 [inline] vivid_probe+0x5ea7/0xb890 drivers/media/test-drivers/vivid/vivid-core.c:2080 platform_probe+0xff/0x1f0 drivers/base/platform.c:1404 call_driver_probe drivers/base/dd.c:579 [inline] really_probe+0x23e/0xa90 drivers/base/dd.c:657 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:799 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:829 __driver_attach+0x283/0x580 drivers/base/dd.c:1215 bus_for_each_dev+0x13b/0x1d0 drivers/base/bus.c:370 bus_add_driver+0x2e9/0x690 drivers/base/bus.c:678 driver_register+0x15c/0x4b0 drivers/base/driver.c:249 vivid_init+0x5eb/0x8c0 drivers/media/test-drivers/vivid/vivid-core.c:2294 do_one_initcall+0x120/0x6e0 init/main.c:1257 Memory state around the buggy address: ffff88814cdf3c80: 05 fc fc fc 05 fc fc fc 05 fc fc fc fa fc fc fc ffff88814cdf3d00: 05 fc fc fc fa fc fc fc fa fc fc fc fa fc fc fc >ffff88814cdf3d80: fa fc fc fc 07 fc fc fc 00 fc fc fc 00 fc fc fc ^ ffff88814cdf3e00: fa fc fc fc 06 fc fc fc 06 fc fc fc 05 fc fc fc ffff88814cdf3e80: 05 fc fc fc fa fc fc fc 00 fc fc fc 00 fc fc fc ==================================================================