syzbot

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BUG: KASAN: use-after-free in xsk_diag_put_info net/xdp/xsk_diag.c:21 [inline]
BUG: KASAN: use-after-free in xsk_diag_fill net/xdp/xsk_diag.c:114 [inline]
BUG: KASAN: use-after-free in xsk_diag_dump+0x1452/0x1970 net/xdp/xsk_diag.c:163
Read of size 4 at addr ffff88807d77c0d8 by task syz-executor.2/23748

CPU: 1 PID: 23748 Comm: syz-executor.2 Not tainted 6.1.50-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:284 [inline]
 print_report+0x15f/0x4f0 mm/kasan/report.c:395
 kasan_report+0x136/0x160 mm/kasan/report.c:495
 xsk_diag_put_info net/xdp/xsk_diag.c:21 [inline]
 xsk_diag_fill net/xdp/xsk_diag.c:114 [inline]
 xsk_diag_dump+0x1452/0x1970 net/xdp/xsk_diag.c:163
 netlink_dump+0x603/0xc50 net/netlink/af_netlink.c:2260
 __netlink_dump_start+0x532/0x6f0 net/netlink/af_netlink.c:2365
 netlink_dump_start include/linux/netlink.h:269 [inline]
 xsk_diag_handler_dump+0x1d5/0x260 net/xdp/xsk_diag.c:190
 sock_diag_rcv_msg+0xd5/0x400
 netlink_rcv_skb+0x1cd/0x410 net/netlink/af_netlink.c:2525
 sock_diag_rcv+0x26/0x40 net/core/sock_diag.c:277
 netlink_unicast_kernel net/netlink/af_netlink.c:1328 [inline]
 netlink_unicast+0x7bf/0x990 net/netlink/af_netlink.c:1354
 netlink_sendmsg+0xa26/0xd60 net/netlink/af_netlink.c:1903
 sock_sendmsg_nosec net/socket.c:716 [inline]
 sock_sendmsg net/socket.c:736 [inline]
 sock_write_iter+0x394/0x4e0 net/socket.c:1113
 do_iter_write+0x6e6/0xc50 fs/read_write.c:861
 vfs_writev fs/read_write.c:934 [inline]
 do_writev+0x27b/0x460 fs/read_write.c:977
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fef51c7cae9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fef507fe0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007fef51d9bf80 RCX: 00007fef51c7cae9
RDX: 0000000000000001 RSI: 0000000020000080 RDI: 0000000000000005
RBP: 00007fef51cc847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fef51d9bf80 R15: 00007fffdd90f7f8
 </TASK>

Allocated by task 23273:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0x97/0xb0 mm/kasan/common.c:383
 kasan_kmalloc include/linux/kasan.h:211 [inline]
 __do_kmalloc_node mm/slab_common.c:955 [inline]
 __kmalloc+0xb2/0x230 mm/slab_common.c:968
 kmalloc include/linux/slab.h:558 [inline]
 tomoyo_realpath_from_path+0xcb/0x5d0 security/tomoyo/realpath.c:251
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_check_open_permission+0x22c/0x490 security/tomoyo/file.c:771
 security_file_open+0x5f/0xa0 security/security.c:1649
 do_dentry_open+0x308/0x10f0 fs/open.c:869
 do_open fs/namei.c:3557 [inline]
 path_openat+0x2644/0x2e60 fs/namei.c:3714
 do_filp_open+0x230/0x480 fs/namei.c:3741
 do_sys_openat2+0x13b/0x500 fs/open.c:1318
 do_sys_open fs/open.c:1334 [inline]
 __do_sys_openat fs/open.c:1350 [inline]
 __se_sys_openat fs/open.c:1345 [inline]
 __x64_sys_openat+0x243/0x290 fs/open.c:1345
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Freed by task 23273:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516
 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236
 kasan_slab_free include/linux/kasan.h:177 [inline]
 slab_free_hook mm/slub.c:1724 [inline]
 slab_free_freelist_hook mm/slub.c:1750 [inline]
 slab_free mm/slub.c:3661 [inline]
 __kmem_cache_free+0x25c/0x3c0 mm/slub.c:3674
 tomoyo_realpath_from_path+0x59f/0x5d0 security/tomoyo/realpath.c:286
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_check_open_permission+0x22c/0x490 security/tomoyo/file.c:771
 security_file_open+0x5f/0xa0 security/security.c:1649
 do_dentry_open+0x308/0x10f0 fs/open.c:869
 do_open fs/namei.c:3557 [inline]
 path_openat+0x2644/0x2e60 fs/namei.c:3714
 do_filp_open+0x230/0x480 fs/namei.c:3741
 do_sys_openat2+0x13b/0x500 fs/open.c:1318
 do_sys_open fs/open.c:1334 [inline]
 __do_sys_openat fs/open.c:1350 [inline]
 __se_sys_openat fs/open.c:1345 [inline]
 __x64_sys_openat+0x243/0x290 fs/open.c:1345
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

The buggy address belongs to the object at ffff88807d77c000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 216 bytes inside of
 4096-byte region [ffff88807d77c000, ffff88807d77d000)

The buggy address belongs to the physical page:
page:ffffea0001f5de00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7d778
head:ffffea0001f5de00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffffea0001f5b000 dead000000000002 ffff888012442140
raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 12603, tgid 12603 (syz-executor.2), ts 808901515903, free_ts 808858376761
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2533
 prep_new_page mm/page_alloc.c:2540 [inline]
 get_page_from_freelist+0x32ed/0x3480 mm/page_alloc.c:4292
 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5559
 alloc_slab_page+0x6a/0x150 mm/slub.c:1794
 allocate_slab mm/slub.c:1939 [inline]
 new_slab+0x84/0x2d0 mm/slub.c:1992
 ___slab_alloc+0xa71/0x1080 mm/slub.c:3180
 __slab_alloc mm/slub.c:3279 [inline]
 slab_alloc_node mm/slub.c:3364 [inline]
 __kmem_cache_alloc_node+0x19f/0x260 mm/slub.c:3437
 __do_kmalloc_node mm/slab_common.c:954 [inline]
 __kmalloc+0xa1/0x230 mm/slab_common.c:968
 kmalloc include/linux/slab.h:558 [inline]
 tomoyo_realpath_from_path+0xcb/0x5d0 security/tomoyo/realpath.c:251
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x273/0x6b0 security/tomoyo/file.c:822
 tomoyo_path_symlink+0xda/0x110 security/tomoyo/tomoyo.c:199
 security_path_symlink+0xd9/0x130 security/security.c:1184
 do_symlinkat+0x129/0x600 fs/namei.c:4425
 __do_sys_symlinkat fs/namei.c:4447 [inline]
 __se_sys_symlinkat fs/namei.c:4444 [inline]
 __x64_sys_symlinkat+0x95/0xa0 fs/namei.c:4444
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1460 [inline]
 free_pcp_prepare mm/page_alloc.c:1510 [inline]
 free_unref_page_prepare+0xf63/0x1120 mm/page_alloc.c:3388
 free_unref_page+0x98/0x570 mm/page_alloc.c:3484
 qlist_free_all+0x22/0x60 mm/kasan/quarantine.c:187
 kasan_quarantine_reduce+0x162/0x180 mm/kasan/quarantine.c:294
 __kasan_slab_alloc+0x1f/0x70 mm/kasan/common.c:305
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook+0x50/0x370 mm/slab.h:737
 slab_alloc_node mm/slub.c:3398 [inline]
 slab_alloc mm/slub.c:3406 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3413 [inline]
 kmem_cache_alloc+0x10c/0x2d0 mm/slub.c:3422
 kmem_cache_zalloc include/linux/slab.h:679 [inline]
 jbd2_alloc_handle include/linux/jbd2.h:1591 [inline]
 new_handle fs/jbd2/transaction.c:476 [inline]
 jbd2__journal_start+0x144/0x5c0 fs/jbd2/transaction.c:503
 __ext4_journal_start_sb+0x19b/0x410 fs/ext4/ext4_jbd2.c:105
 __ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline]
 __ext4_unlink+0x412/0xba0 fs/ext4/namei.c:3260
 ext4_unlink+0x1d5/0x670 fs/ext4/namei.c:3319
 vfs_unlink+0x359/0x5f0 fs/namei.c:4252
 do_unlinkat+0x49d/0x940 fs/namei.c:4320
 __do_sys_unlink fs/namei.c:4368 [inline]
 __se_sys_unlink fs/namei.c:4366 [inline]
 __x64_sys_unlink+0x45/0x50 fs/namei.c:4366
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Memory state around the buggy address:
 ffff88807d77bf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88807d77c000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807d77c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                    ^
 ffff88807d77c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807d77c180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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