syzbot

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BUG: KMSAN: uninit-value in ppp_sync_txmunge drivers/net/ppp/ppp_synctty.c:516 [inline]
BUG: KMSAN: uninit-value in ppp_sync_send+0x21c/0xb00 drivers/net/ppp/ppp_synctty.c:568
 ppp_sync_txmunge drivers/net/ppp/ppp_synctty.c:516 [inline]
 ppp_sync_send+0x21c/0xb00 drivers/net/ppp/ppp_synctty.c:568
 ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2280 [inline]
 ppp_input+0x1f1/0xe60 drivers/net/ppp/ppp_generic.c:2304
 pppoe_rcv_core+0x1d3/0x720 drivers/net/ppp/pppoe.c:379
 sk_backlog_rcv+0x13b/0x420 include/net/sock.h:1115
 __release_sock+0x1da/0x330 net/core/sock.c:3072
 release_sock+0x6b/0x250 net/core/sock.c:3626
 pppoe_sendmsg+0x2b8/0xb90 drivers/net/ppp/pppoe.c:903
 sock_sendmsg_nosec net/socket.c:729 [inline]
 __sock_sendmsg+0x30f/0x380 net/socket.c:744
 ____sys_sendmsg+0x903/0xb60 net/socket.c:2607
 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2661
 __sys_sendmmsg+0x3c1/0x960 net/socket.c:2747
 __do_sys_sendmmsg net/socket.c:2776 [inline]
 __se_sys_sendmmsg net/socket.c:2773 [inline]
 __x64_sys_sendmmsg+0xbc/0x120 net/socket.c:2773
 x64_sys_call+0xb6e/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:308
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:4091 [inline]
 slab_alloc_node mm/slub.c:4134 [inline]
 kmem_cache_alloc_node_noprof+0x6bf/0xb80 mm/slub.c:4186
 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:587
 __alloc_skb+0x363/0x7b0 net/core/skbuff.c:678
 alloc_skb include/linux/skbuff.h:1322 [inline]
 sock_wmalloc+0xfe/0x1a0 net/core/sock.c:2732
 pppoe_sendmsg+0x3a7/0xb90 drivers/net/ppp/pppoe.c:867
 sock_sendmsg_nosec net/socket.c:729 [inline]
 __sock_sendmsg+0x30f/0x380 net/socket.c:744
 ____sys_sendmsg+0x903/0xb60 net/socket.c:2607
 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2661
 __sys_sendmmsg+0x3c1/0x960 net/socket.c:2747
 __do_sys_sendmmsg net/socket.c:2776 [inline]
 __se_sys_sendmmsg net/socket.c:2773 [inline]
 __x64_sys_sendmmsg+0xbc/0x120 net/socket.c:2773
 x64_sys_call+0xb6e/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:308
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 0 UID: 0 PID: 18206 Comm: syz.4.2821 Not tainted 6.12.0-rc3-syzkaller-00013-geca631b8fe80 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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