[syzbot] [bpf?] KASAN: slab-use-after-free Read in do_check

[syzbot <syzbot+b5eb72a560b8149a1885@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    19a60293b992 Add linux-next specific files for 20250611
git tree:       linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=15472d70580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=76ed3656d7159e27
dashboard link: https://syzkaller.appspot.com/bug?extid=b5eb72a560b8149a1885
compiler:       Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16af860c580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=174db60c580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/c453c11565fa/disk-19a60293.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/4034ded42b2e/vmlinux-19a60293.xz
kernel image: https://storage.googleapis.com/syzbot-assets/5355903cdb8f/bzImage-19a60293.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b5eb72a560b8149a1885@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in do_check+0xb388/0xe170 kernel/bpf/verifier.c:19756
Read of size 1 at addr ffff88801deeef79 by task syz-executor672/5842

CPU: 1 UID: 0 PID: 5842 Comm: syz-executor672 Not tainted 6.16.0-rc1-next-20250611-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 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: 0033:0x7f7586cdbeb9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 17 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc2e683128 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7586cdbeb9
RDX: 0000000000000094 RSI: 0000200000000840 RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000006
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000001
 </TASK>

Allocated by task 5842:
 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 5842:
 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 ffff88801deeef00
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 121 bytes inside of
 freed 192-byte region [ffff88801deeef00, ffff88801deeefc0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1deee
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801a4413c0 ffffea00006fca40 dead000000000004
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 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1, tgid 1 (swapper/0), ts 2954361175, free_ts 2954343552
 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]
 __do_kmalloc_node mm/slub.c:4327 [inline]
 __kmalloc_node_noprof+0x2fd/0x4e0 mm/slub.c:4334
 kmalloc_node_noprof include/linux/slab.h:932 [inline]
 __vmalloc_area_node mm/vmalloc.c:3690 [inline]
 __vmalloc_node_range_noprof+0x5a9/0x12f0 mm/vmalloc.c:3885
 vmalloc_huge_node_noprof+0xb3/0xf0 mm/vmalloc.c:4001
 vmalloc_huge include/linux/vmalloc.h:185 [inline]
 alloc_large_system_hash+0x2b8/0x5e0 mm/mm_init.c:2515
 posixtimer_init+0x140/0x270 kernel/time/posix-timers.c:1561
 do_one_initcall+0x233/0x820 init/main.c:1274
 do_initcall_level+0x137/0x1f0 init/main.c:1336
 do_initcalls+0x69/0xd0 init/main.c:1352
 kernel_init_freeable+0x3d9/0x570 init/main.c:1584
 kernel_init+0x1d/0x1d0 init/main.c:1474
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:1248 [inline]
 __free_frozen_pages+0xc71/0xe70 mm/page_alloc.c:2706
 __kasan_populate_vmalloc mm/kasan/shadow.c:383 [inline]
 kasan_populate_vmalloc+0x18a/0x1a0 mm/kasan/shadow.c:417
 alloc_vmap_area+0xd51/0x1490 mm/vmalloc.c:2084
 __get_vm_area_node+0x1f8/0x300 mm/vmalloc.c:3179
 __vmalloc_node_range_noprof+0x301/0x12f0 mm/vmalloc.c:3845
 vmalloc_huge_node_noprof+0xb3/0xf0 mm/vmalloc.c:4001
 vmalloc_huge include/linux/vmalloc.h:185 [inline]
 alloc_large_system_hash+0x2b8/0x5e0 mm/mm_init.c:2515
 posixtimer_init+0x140/0x270 kernel/time/posix-timers.c:1561
 do_one_initcall+0x233/0x820 init/main.c:1274
 do_initcall_level+0x137/0x1f0 init/main.c:1336
 do_initcalls+0x69/0xd0 init/main.c:1352
 kernel_init_freeable+0x3d9/0x570 init/main.c:1584
 kernel_init+0x1d/0x1d0 init/main.c:1474
 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:
 ffff88801deeee00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88801deeee80: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc
>ffff88801deeef00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                                ^
 ffff88801deeef80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff88801deef000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================


---
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