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BUG: KMSAN: kernel-infoleak in kmsan_copy_to_user+0x9c/0xb0 mm/kmsan/kmsan_hooks.c:249
CPU: 0 PID: 13522 Comm: syz-executor.3 Not tainted 5.12.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x24c/0x2e0 lib/dump_stack.c:120
 kmsan_report+0xfb/0x1e0 mm/kmsan/kmsan_report.c:121
 kmsan_internal_check_memory+0x469/0x500 mm/kmsan/kmsan.c:433
 kmsan_copy_to_user+0x9c/0xb0 mm/kmsan/kmsan_hooks.c:249
 instrument_copy_to_user include/linux/instrumented.h:121 [inline]
 copyout lib/iov_iter.c:145 [inline]
 copy_page_to_iter_iovec lib/iov_iter.c:220 [inline]
 copy_page_to_iter+0xac4/0x2230 lib/iov_iter.c:915
 pipe_read+0x9fc/0x22e0 fs/pipe.c:290
 call_read_iter include/linux/fs.h:1971 [inline]
 new_sync_read fs/read_write.c:415 [inline]
 vfs_read+0x136b/0x15a0 fs/read_write.c:496
 ksys_read+0x275/0x500 fs/read_write.c:634
 __do_sys_read fs/read_write.c:644 [inline]
 __se_sys_read+0x92/0xb0 fs/read_write.c:642
 __x64_sys_read+0x4a/0x70 fs/read_write.c:642
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665d9
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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fba34191188 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9
RDX: 0000000000002020 RSI: 0000000020004080 RDI: 0000000000000004
RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 0000000000a9fb1f R14: 00007fba34191300 R15: 0000000000022000

Uninit was created at:
 kmsan_save_stack_with_flags+0x3c/0x90 mm/kmsan/kmsan.c:120
 kmsan_alloc_page+0xd0/0x1e0 mm/kmsan/kmsan_shadow.c:273
 __alloc_pages_nodemask+0x827/0xf90 mm/page_alloc.c:5044
 alloc_pages_current+0x7b6/0xb60 mm/mempolicy.c:2277
 alloc_pages include/linux/gfp.h:561 [inline]
 push_pipe+0x74c/0xd00 lib/iov_iter.c:528
 __pipe_get_pages lib/iov_iter.c:1288 [inline]
 pipe_get_pages lib/iov_iter.c:1321 [inline]
 iov_iter_get_pages+0x1aef/0x2000 lib/iov_iter.c:1332
 af_alg_make_sg+0xf3/0x780 crypto/af_alg.c:410
 af_alg_get_rsgl+0x7d1/0xe80 crypto/af_alg.c:1168
 _skcipher_recvmsg crypto/algif_skcipher.c:77 [inline]
 skcipher_recvmsg+0x6e2/0x1ab0 crypto/algif_skcipher.c:157
 sock_recvmsg_nosec net/socket.c:888 [inline]
 sock_recvmsg net/socket.c:906 [inline]
 sock_read_iter+0x59a/0x620 net/socket.c:979
 call_read_iter include/linux/fs.h:1971 [inline]
 generic_file_splice_read+0x74b/0xb70 fs/splice.c:311
 sock_splice_read+0x241/0x250 net/socket.c:957
 do_splice_to fs/splice.c:796 [inline]
 splice_file_to_pipe+0x7c1/0xa90 fs/splice.c:1018
 do_splice+0x2ab7/0x2c10 fs/splice.c:1104
 __do_splice fs/splice.c:1144 [inline]
 __do_sys_splice fs/splice.c:1350 [inline]
 __se_sys_splice+0x8fa/0xb50 fs/splice.c:1332
 __x64_sys_splice+0x6e/0x90 fs/splice.c:1332
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Bytes 0-4095 of 4096 are uninitialized
Memory access of size 4096 starts at ffff8881207d8000
Data copied to user address 0000000020004080
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