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BUG: KASAN: slab-out-of-bounds in iov_iter_revert+0x1c1/0x590 lib/iov_iter.c:633
Read of size 4 at addr ffff8880611bb538 by task syz.1.699/10198

CPU: 1 UID: 0 PID: 10198 Comm: syz.1.699 Not tainted 6.14.0-rc7-syzkaller-00205-g586de92313fc #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0x16e/0x5b0 mm/kasan/report.c:521
 kasan_report+0x143/0x180 mm/kasan/report.c:634
 iov_iter_revert+0x1c1/0x590 lib/iov_iter.c:633
 p9_client_write+0x444/0x7a0 net/9p/client.c:1669
 v9fs_issue_write+0xf0/0x1d0 fs/9p/vfs_addr.c:59
 netfs_do_issue_write fs/netfs/write_issue.c:239 [inline]
 netfs_issue_write fs/netfs/write_issue.c:269 [inline]
 netfs_end_issue_write+0x18f/0x420 fs/netfs/write_issue.c:541
 netfs_unbuffered_write+0x589/0x600 fs/netfs/write_issue.c:733
 netfs_unbuffered_write_iter_locked+0x456/0x9f0 fs/netfs/direct_write.c:100
 netfs_unbuffered_write_iter+0x4e1/0x6a0 fs/netfs/direct_write.c:195
 new_sync_write fs/read_write.c:586 [inline]
 vfs_write+0xad1/0xd10 fs/read_write.c:679
 ksys_write+0x18f/0x2b0 fs/read_write.c:731
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbb4d18d169
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:00007fbb4df84038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fbb4d3a5fa0 RCX: 00007fbb4d18d169
RDX: 0000000000000050 RSI: 0000200000000700 RDI: 0000000000000007
RBP: 00007fbb4d20e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fbb4d3a5fa0 R15: 00007ffdc1b22858
 </TASK>

Allocated by task 7900:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4294 [inline]
 __kmalloc_node_noprof+0x290/0x4d0 mm/slub.c:4300
 __kvmalloc_node_noprof+0x72/0x190 mm/util.c:665
 xt_jumpstack_alloc net/netfilter/x_tables.c:1355 [inline]
 xt_replace_table+0x1a2/0x780 net/netfilter/x_tables.c:1394
 __do_replace+0x1ae/0xa40 net/ipv4/netfilter/ip_tables.c:1064
 do_replace net/ipv4/netfilter/ip_tables.c:1141 [inline]
 do_ipt_set_ctl+0xf02/0x1250 net/ipv4/netfilter/ip_tables.c:1635
 nf_setsockopt+0x297/0x2c0 net/netfilter/nf_sockopt.c:101
 do_sock_setsockopt+0x3b1/0x720 net/socket.c:2303
 __sys_setsockopt net/socket.c:2328 [inline]
 __do_sys_setsockopt net/socket.c:2334 [inline]
 __se_sys_setsockopt net/socket.c:2331 [inline]
 __x64_sys_setsockopt+0x1ee/0x280 net/socket.c:2331
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 7900:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2353 [inline]
 slab_free mm/slub.c:4609 [inline]
 kfree+0x196/0x430 mm/slub.c:4757
 xt_free_table_info+0xef/0x160 net/netfilter/x_tables.c:1209
 __do_replace+0x7dd/0xa40 net/ipv4/netfilter/ip_tables.c:1084
 do_replace net/ipv4/netfilter/ip_tables.c:1141 [inline]
 do_ipt_set_ctl+0xf02/0x1250 net/ipv4/netfilter/ip_tables.c:1635
 nf_setsockopt+0x297/0x2c0 net/netfilter/nf_sockopt.c:101
 do_sock_setsockopt+0x3b1/0x720 net/socket.c:2303
 __sys_setsockopt net/socket.c:2328 [inline]
 __do_sys_setsockopt net/socket.c:2334 [inline]
 __se_sys_setsockopt net/socket.c:2331 [inline]
 __x64_sys_setsockopt+0x1ee/0x280 net/socket.c:2331
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8880611bb520
 which belongs to the cache kmalloc-16 of size 16
The buggy address is located 8 bytes to the right of
 allocated 16-byte region [ffff8880611bb520, ffff8880611bb530)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x611bb
anon flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801b041640 0000000000000000 dead000000000001
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 0x252800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_THISNODE), pid 7576, tgid 7576 (syz-executor), ts 350080631254, free_ts 348465182316
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1551
 prep_new_page mm/page_alloc.c:1559 [inline]
 get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3477
 __alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4740
 alloc_slab_page mm/slub.c:2425 [inline]
 allocate_slab+0x66/0x3a0 mm/slub.c:2587
 new_slab mm/slub.c:2640 [inline]
 ___slab_alloc+0xc27/0x14a0 mm/slub.c:3826
 __slab_alloc+0x58/0xa0 mm/slub.c:3916
 __slab_alloc_node mm/slub.c:3991 [inline]
 slab_alloc_node mm/slub.c:4152 [inline]
 __do_kmalloc_node mm/slub.c:4293 [inline]
 __kmalloc_node_noprof+0x2ee/0x4d0 mm/slub.c:4300
 __kvmalloc_node_noprof+0x72/0x190 mm/util.c:665
 xt_jumpstack_alloc net/netfilter/x_tables.c:1355 [inline]
 xt_replace_table+0x1a2/0x780 net/netfilter/x_tables.c:1394
 __do_replace+0x1ae/0xa50 net/ipv6/netfilter/ip6_tables.c:1081
 do_replace net/ipv6/netfilter/ip6_tables.c:1158 [inline]
 do_ip6t_set_ctl+0xf11/0x1270 net/ipv6/netfilter/ip6_tables.c:1644
 nf_setsockopt+0x297/0x2c0 net/netfilter/nf_sockopt.c:101
 do_sock_setsockopt+0x3b1/0x720 net/socket.c:2303
 __sys_setsockopt net/socket.c:2328 [inline]
 __do_sys_setsockopt net/socket.c:2334 [inline]
 __se_sys_setsockopt net/socket.c:2331 [inline]
 __x64_sys_setsockopt+0x1ee/0x280 net/socket.c:2331
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 5903 tgid 5903 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_frozen_pages+0xe0d/0x10e0 mm/page_alloc.c:2660
 vfree+0x1c3/0x360 mm/vmalloc.c:3383
 delayed_vfree_work+0x56/0x80 mm/vmalloc.c:3303
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xac0/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd30 kernel/workqueue.c:3400
 kthread+0x7ab/0x920 kernel/kthread.c:464
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Memory state around the buggy address:
 ffff8880611bb400: 00 00 fc fc fa fb fc fc fa fb fc fc 00 00 fc fc
 ffff8880611bb480: fa fb fc fc fa fb fc fc fa fb fc fc fa fb fc fc
>ffff8880611bb500: 00 00 fc fc fa fb fc fc 00 00 fc fc 00 00 fc fc
                                        ^
 ffff8880611bb580: fa fb fc fc fa fb fc fc 00 00 fc fc 00 00 fc fc
 ffff8880611bb600: 00 00 fc fc fa fb fc fc 00 00 fc fc 00 00 fc fc
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