================================================================== BUG: KASAN: slab-use-after-free in do_check+0xb388/0xe170 kernel/bpf/verifier.c:19756 Read of size 1 at addr ffff888033c07779 by task syz.4.960/8326 CPU: 0 UID: 0 PID: 8326 Comm: syz.4.960 Not tainted 6.15.0-syzkaller-g3b55a9e6738b #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xd2/0x2b0 mm/kasan/report.c:521 kasan_report+0x118/0x150 mm/kasan/report.c:634 do_check+0xb388/0xe170 kernel/bpf/verifier.c:19756 do_check_common+0x168d/0x20b0 kernel/bpf/verifier.c:22905 do_check_main kernel/bpf/verifier.c:22996 [inline] bpf_check+0x1381e/0x19e50 kernel/bpf/verifier.c:24162 bpf_prog_load+0x1318/0x1930 kernel/bpf/syscall.c:2972 __sys_bpf+0x5f1/0x860 kernel/bpf/syscall.c:5978 __do_sys_bpf kernel/bpf/syscall.c:6085 [inline] __se_sys_bpf kernel/bpf/syscall.c:6083 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6083 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa3f898e929 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:00007fa3f97cc038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fa3f8bb5fa0 RCX: 00007fa3f898e929 RDX: 0000000000000094 RSI: 0000200000002c40 RDI: 0000000000000005 RBP: 00007fa3f8a10b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fa3f8bb5fa0 R15: 00007fff6e55a758 Allocated by task 8326: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4359 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] do_check_common+0x13f/0x20b0 kernel/bpf/verifier.c:22798 do_check_main kernel/bpf/verifier.c:22996 [inline] bpf_check+0x1381e/0x19e50 kernel/bpf/verifier.c:24162 bpf_prog_load+0x1318/0x1930 kernel/bpf/syscall.c:2972 __sys_bpf+0x5f1/0x860 kernel/bpf/syscall.c:5978 __do_sys_bpf kernel/bpf/syscall.c:6085 [inline] __se_sys_bpf kernel/bpf/syscall.c:6083 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6083 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 8326: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4643 [inline] kfree+0x18e/0x440 mm/slub.c:4842 push_stack+0x247/0x3c0 kernel/bpf/verifier.c:2069 check_cond_jmp_op+0x1069/0x2340 kernel/bpf/verifier.c:16562 do_check_insn kernel/bpf/verifier.c:19621 [inline] do_check+0x672c/0xe170 kernel/bpf/verifier.c:19755 do_check_common+0x168d/0x20b0 kernel/bpf/verifier.c:22905 do_check_main kernel/bpf/verifier.c:22996 [inline] bpf_check+0x1381e/0x19e50 kernel/bpf/verifier.c:24162 bpf_prog_load+0x1318/0x1930 kernel/bpf/syscall.c:2972 __sys_bpf+0x5f1/0x860 kernel/bpf/syscall.c:5978 __do_sys_bpf kernel/bpf/syscall.c:6085 [inline] __se_sys_bpf kernel/bpf/syscall.c:6083 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6083 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888033c07700 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 121 bytes inside of freed 192-byte region [ffff888033c07700, ffff888033c077c0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x33c07 anon flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801a4413c0 ffffea0000913480 dead000000000005 raw: 0000000000000000 0000000000100010 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 28051850835, free_ts 28037747238 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704 prep_new_page mm/page_alloc.c:1712 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3669 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419 alloc_slab_page mm/slub.c:2451 [inline] allocate_slab+0x8a/0x3b0 mm/slub.c:2619 new_slab mm/slub.c:2673 [inline] ___slab_alloc+0xbfc/0x1480 mm/slub.c:3859 __slab_alloc mm/slub.c:3949 [inline] __slab_alloc_node mm/slub.c:4024 [inline] slab_alloc_node mm/slub.c:4185 [inline] __kmalloc_cache_noprof+0x296/0x3d0 mm/slub.c:4354 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] call_usermodehelper_setup+0x8e/0x270 kernel/umh.c:362 kobject_uevent_env+0x65c/0x8c0 lib/kobject_uevent.c:628 kernel_add_sysfs_param+0x100/0x130 kernel/params.c:815 param_sysfs_builtin+0x1de/0x290 kernel/params.c:850 param_sysfs_builtin_init+0x32/0x40 kernel/params.c:986 do_one_initcall+0x233/0x820 init/main.c:1273 do_initcall_level+0x137/0x1f0 init/main.c:1335 do_initcalls+0x69/0xd0 init/main.c:1351 kernel_init_freeable+0x3d9/0x570 init/main.c:1583 page last free pid 977 tgid 977 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0xc71/0xe70 mm/page_alloc.c:2706 vfree+0x25a/0x400 mm/vmalloc.c:3426 delayed_vfree_work+0x55/0x80 mm/vmalloc.c:3345 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff888033c07600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888033c07680: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff888033c07700: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888033c07780: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888033c07800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================