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BUG: KASAN: stack-out-of-bounds in iov_iter_revert+0x4d5/0x5f0 lib/iov_iter.c:645
Read of size 8 at addr ffffc90003847b58 by task syz.0.17/5946

CPU: 0 UID: 0 PID: 5946 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 iov_iter_revert+0x4d5/0x5f0 lib/iov_iter.c:645
 skb_zerocopy_iter_stream+0x27d/0x660 net/core/skbuff.c:1911
 tcp_sendmsg_locked+0x1815/0x5540 net/ipv4/tcp.c:1300
 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1412
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x19c/0x270 net/socket.c:742
 ____sys_sendmsg+0x52d/0x830 net/socket.c:2630
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2684
 __sys_sendmmsg+0x227/0x430 net/socket.c:2773
 __do_sys_sendmmsg net/socket.c:2800 [inline]
 __se_sys_sendmmsg net/socket.c:2797 [inline]
 __x64_sys_sendmmsg+0xa0/0xc0 net/socket.c:2797
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe7c078f749
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:00007fe7c1647038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007fe7c09e5fa0 RCX: 00007fe7c078f749
RDX: 0000000000000004 RSI: 0000200000000d00 RDI: 0000000000000003
RBP: 00007fe7c0813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000004000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe7c09e6038 R14: 00007fe7c09e5fa0 R15: 00007ffd19e95ea8
 </TASK>

The buggy address belongs to stack of task syz.0.17/5946
 and is located at offset 280 in frame:
 ___sys_sendmsg+0x0/0x2a0 net/socket.c:2713

This frame has 4 objects:
 [32, 88) 'msg.i.i'
 [128, 256) 'address'
 [288, 416) 'iovstack'
 [448, 456) 'iov'

The buggy address belongs to a 8-page vmalloc region starting at 0xffffc90003840000 allocated at copy_process+0x54b/0x3c00 kernel/fork.c:2012
The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1135fc
memcg:ffff88810c5ca102
flags: 0x17ff00000000000(node=0|zone=2|lastcpupid=0x7ff)
raw: 017ff00000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff ffff88810c5ca102
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x2dc2(GFP_KERNEL|__GFP_HIGHMEM|__GFP_ZERO|__GFP_NOWARN), pid 5869, tgid 5869 (syz-executor), ts 56973482428, free_ts 56803199363
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x234/0x290 mm/page_alloc.c:1845
 prep_new_page mm/page_alloc.c:1853 [inline]
 get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3879
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5178
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416
 alloc_frozen_pages_noprof mm/mempolicy.c:2487 [inline]
 alloc_pages_noprof+0xa9/0x190 mm/mempolicy.c:2507
 vm_area_alloc_pages mm/vmalloc.c:3647 [inline]
 __vmalloc_area_node mm/vmalloc.c:3724 [inline]
 __vmalloc_node_range_noprof+0x96c/0x12d0 mm/vmalloc.c:3897
 __vmalloc_node_noprof+0xc2/0x110 mm/vmalloc.c:3960
 alloc_thread_stack_node kernel/fork.c:311 [inline]
 dup_task_struct+0x3d4/0x830 kernel/fork.c:881
 copy_process+0x54b/0x3c00 kernel/fork.c:2012
 kernel_clone+0x21e/0x840 kernel/fork.c:2609
 __do_sys_clone kernel/fork.c:2750 [inline]
 __se_sys_clone kernel/fork.c:2734 [inline]
 __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2734
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 5845 tgid 5845 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1394 [inline]
 __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2901
 kasan_depopulate_vmalloc_pte+0x6d/0x90 mm/kasan/shadow.c:495
 apply_to_pte_range mm/memory.c:3143 [inline]
 apply_to_pmd_range mm/memory.c:3187 [inline]
 apply_to_pud_range mm/memory.c:3223 [inline]
 apply_to_p4d_range mm/memory.c:3259 [inline]
 __apply_to_page_range+0xb66/0x13d0 mm/memory.c:3295
 kasan_release_vmalloc+0xa2/0xd0 mm/kasan/shadow.c:616
 kasan_release_vmalloc_node mm/vmalloc.c:2255 [inline]
 purge_vmap_node+0x214/0x8f0 mm/vmalloc.c:2272
 __purge_vmap_area_lazy+0x7a4/0xb40 mm/vmalloc.c:2362
 drain_vmap_area_work+0x27/0x40 mm/vmalloc.c:2396
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffffc90003847a00: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 00 00
 ffffc90003847a80: 00 00 00 f2 f2 f2 f2 f2 00 00 00 00 00 00 00 00
>ffffc90003847b00: 00 00 00 00 00 00 00 00 f2 f2 f2 f2 00 00 00 00
                                                    ^
 ffffc90003847b80: 00 00 00 00 00 00 00 00 00 00 00 00 f2 f2 f2 f2
 ffffc90003847c00: 00 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00
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