Hello,

syzbot found the following issue on:

HEAD commit:    a975094bf98c Merge tag 'exfat-for-7.2-rc1' of git://git.ke..
git tree:       bpf-next
console output: https://syzkaller.appspot.com/x/log.txt?x=14c0eba1580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=9519196b0a0d47bc
dashboard link: https://syzkaller.appspot.com/bug?extid=0ac4d84afe1066a1f3e9
compiler:       Debian clang version 22.1.6 (++20260514074242+fc4aad7b5db3-1~exp1~20260514074407.73), Debian LLD 22.1.6

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/25ab9553b7ce/disk-a975094b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/5498f6d5131a/vmlinux-a975094b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/90c6fca52c8c/bzImage-a975094b.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0ac4d84afe1066a1f3e9@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: stack-out-of-bounds in jhash2 include/linux/jhash.h:138 [inline]
BUG: KASAN: stack-out-of-bounds in __xfrm6_addr_hash net/xfrm/xfrm_hash.h:16 [inline]
BUG: KASAN: stack-out-of-bounds in __xfrm6_daddr_saddr_hash net/xfrm/xfrm_hash.h:29 [inline]
BUG: KASAN: stack-out-of-bounds in __xfrm_dst_hash net/xfrm/xfrm_hash.h:95 [inline]
BUG: KASAN: stack-out-of-bounds in xfrm_state_find+0x590d/0x5ec0 net/xfrm/xfrm_state.c:1421
Read of size 4 at addr ffffc900061a7908 by task syz.8.4714/27393

CPU: 1 UID: 0 PID: 27393 Comm: syz.8.4714 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 jhash2 include/linux/jhash.h:138 [inline]
 __xfrm6_addr_hash net/xfrm/xfrm_hash.h:16 [inline]
 __xfrm6_daddr_saddr_hash net/xfrm/xfrm_hash.h:29 [inline]
 __xfrm_dst_hash net/xfrm/xfrm_hash.h:95 [inline]
 xfrm_state_find+0x590d/0x5ec0 net/xfrm/xfrm_state.c:1421
 xfrm_tmpl_resolve_one net/xfrm/xfrm_policy.c:2513 [inline]
 xfrm_tmpl_resolve net/xfrm/xfrm_policy.c:2564 [inline]
 xfrm_resolve_and_create_bundle+0x7f3/0x3070 net/xfrm/xfrm_policy.c:2862
 xfrm_bundle_lookup net/xfrm/xfrm_policy.c:3097 [inline]
 xfrm_lookup_with_ifid+0x576/0x1b40 net/xfrm/xfrm_policy.c:3228
 xfrm_lookup net/xfrm/xfrm_policy.c:3327 [inline]
 xfrm_lookup_route+0x3c/0x1c0 net/xfrm/xfrm_policy.c:3338
 raw_sendmsg+0x110d/0x1a20 net/ipv4/raw.c:628
 sock_sendmsg_nosec+0x10e/0x180 net/socket.c:776
 __sock_sendmsg net/socket.c:790 [inline]
 ____sys_sendmsg+0x54e/0x850 net/socket.c:2684
 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2738
 __sys_sendmsg net/socket.c:2770 [inline]
 __do_sys_sendmsg net/socket.c:2775 [inline]
 __se_sys_sendmsg net/socket.c:2773 [inline]
 __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2773
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7feeebb9ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007feeeca26028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007feeebe15fa0 RCX: 00007feeebb9ce59
RDX: 000000000400c894 RSI: 0000200000000900 RDI: 0000000000000007
RBP: 00007feeebc32e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007feeebe16038 R14: 00007feeebe15fa0 R15: 00007fff5f12fac8
 </TASK>

The buggy address belongs to stack of task syz.8.4714/27393
 and is located at offset 328 in frame:
 raw_sendmsg+0x0/0x1a20 net/ipv4/raw.c:909

This frame has 5 objects:
 [32, 104) 'opt_copy_u'
 [144, 200) 'ipc'
 [240, 248) 'rt'
 [272, 328) 'fl4'
 [368, 392) 'rfv'

The buggy address belongs to a 8-page vmalloc region starting at 0xffffc900061a0000 allocated at copy_process+0x81b/0x42e0 kernel/fork.c:2110
The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x8b157
memcg:ffff88807cfe5e02
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 0000000000000000 ffffea00022c55c8 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff ffff88807cfe5e02
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x29c2(GFP_NOWAIT|__GFP_HIGHMEM|__GFP_IO|__GFP_FS|__GFP_ZERO), pid 27358, tgid 27357 (syz.3.4705), ts 776904415615, free_ts 773990322016
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1859
 prep_new_page mm/page_alloc.c:1867 [inline]
 get_page_from_freelist+0x21fa/0x2270 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5304
 alloc_pages_mpol+0x212/0x380 mm/mempolicy.c:2490
 alloc_frozen_pages_noprof mm/mempolicy.c:2561 [inline]
 alloc_pages_noprof+0xac/0x2a0 mm/mempolicy.c:2581
 vm_area_alloc_pages mm/vmalloc.c:3667 [inline]
 __vmalloc_area_node mm/vmalloc.c:3892 [inline]
 __vmalloc_node_range_noprof+0x795/0x1730 mm/vmalloc.c:4082
 __vmalloc_node_noprof+0xc2/0x100 mm/vmalloc.c:4143
 alloc_thread_stack_node kernel/fork.c:359 [inline]
 dup_task_struct+0x28e/0x850 kernel/fork.c:929
 copy_process+0x81b/0x42e0 kernel/fork.c:2110
 kernel_clone+0x2d7/0x940 kernel/fork.c:2746
 __do_sys_clone kernel/fork.c:2887 [inline]
 __se_sys_clone kernel/fork.c:2871 [inline]
 __x64_sys_clone+0x1b6/0x230 kernel/fork.c:2871
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 27224 tgid 27224 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1406 [inline]
 __free_frozen_pages+0xc1f/0xd10 mm/page_alloc.c:2950
 __slab_free+0x274/0x2c0 mm/slub.c:5672
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4610 [inline]
 slab_alloc_node mm/slub.c:4939 [inline]
 __do_kmalloc_node mm/slub.c:5333 [inline]
 __kmalloc_noprof+0x312/0x750 mm/slub.c:5347
 _kmalloc_noprof include/linux/slab.h:973 [inline]
 tomoyo_realpath_from_path+0xef/0x640 security/tomoyo/realpath.c:251
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_check_open_permission+0x229/0x470 security/tomoyo/file.c:776
 security_file_open+0xa9/0x240 security/security.c:2739
 do_dentry_open+0x4a0/0x1380 fs/open.c:924
 vfs_open+0x3b/0x340 fs/open.c:1079
 do_open fs/namei.c:4700 [inline]
 path_openat+0x2e44/0x3830 fs/namei.c:4859
 do_file_open+0x23e/0x4a0 fs/namei.c:4888
 do_sys_openat2+0x115/0x200 fs/open.c:1395
 do_sys_open fs/open.c:1401 [inline]
 __do_sys_openat fs/open.c:1417 [inline]
 __se_sys_openat fs/open.c:1412 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1412
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94

Memory state around the buggy address:
 ffffc900061a7800: 00 00 00 00 00 f2 f2 f2 f2 f2 00 00 00 00 00 00
 ffffc900061a7880: 00 f2 f2 f2 f2 f2 00 f2 f2 f2 00 00 00 00 00 00

ffffc900061a7900: 00 f2 f2 f2 f2 f2 00 00 00 f3 f3 f3 f3 f3 f3 f3

                      ^
 ffffc900061a7980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc900061a7a00: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1
==================================================================


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