=====================================================
BUG: KMSAN: uninit-value in number+0x851/0x23d0 lib/vsprintf.c:490 lib/vsprintf.c:490
 number+0x851/0x23d0 lib/vsprintf.c:490 lib/vsprintf.c:490
 vsnprintf+0x1f0d/0x3650 lib/vsprintf.c:2871 lib/vsprintf.c:2871
 seq_vprintf fs/seq_file.c:391 [inline]
 seq_vprintf fs/seq_file.c:391 [inline] fs/seq_file.c:406
 seq_printf+0x314/0x4f0 fs/seq_file.c:406 fs/seq_file.c:406
 udp4_format_sock net/ipv4/udp.c:3062 [inline]
 udp4_format_sock net/ipv4/udp.c:3062 [inline] net/ipv4/udp.c:3084
 udp4_seq_show+0x78b/0x910 net/ipv4/udp.c:3084 net/ipv4/udp.c:3084
 seq_read_iter+0xaac/0x2150 fs/seq_file.c:230 fs/seq_file.c:230
 seq_read+0x7a6/0x990 fs/seq_file.c:162 fs/seq_file.c:162
 pde_read fs/proc/inode.c:311 [inline]
 pde_read fs/proc/inode.c:311 [inline] fs/proc/inode.c:323
 proc_reg_read+0x39d/0x560 fs/proc/inode.c:323 fs/proc/inode.c:323
 do_iter_read+0xb28/0x14c0 fs/read_write.c:788 fs/read_write.c:788
 vfs_readv fs/read_write.c:906 [inline]
 vfs_readv fs/read_write.c:906 [inline] fs/read_write.c:998
 do_preadv+0x45e/0x6c0 fs/read_write.c:998 fs/read_write.c:998
 __do_sys_preadv fs/read_write.c:1048 [inline]
 __se_sys_preadv fs/read_write.c:1043 [inline]
 __do_sys_preadv fs/read_write.c:1048 [inline] fs/read_write.c:1043
 __se_sys_preadv fs/read_write.c:1043 [inline] fs/read_write.c:1043
 __x64_sys_preadv+0x120/0x170 fs/read_write.c:1043 fs/read_write.c:1043
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_x64 arch/x86/entry/common.c:51 [inline] arch/x86/entry/common.c:82
 do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Local variable sample.i created at:
 perf_log_itrace_start kernel/events/core.c:9069 [inline]
 perf_log_itrace_start kernel/events/core.c:9069 [inline] kernel/events/core.c:2557
 event_sched_in+0x132b/0x35c0 kernel/events/core.c:2557 kernel/events/core.c:2557
 group_sched_in kernel/events/core.c:2595 [inline]
 merge_sched_in kernel/events/core.c:3746 [inline]
 group_sched_in kernel/events/core.c:2595 [inline] kernel/events/core.c:3696
 merge_sched_in kernel/events/core.c:3746 [inline] kernel/events/core.c:3696
 visit_groups_merge+0x2919/0x7460 kernel/events/core.c:3696 kernel/events/core.c:3696

CPU: 1 PID: 3642 Comm: syz-executor500 Not tainted 5.16.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
=====================================================