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BUG: KMSAN: uninit-value in pptp_xmit+0xc9a/0x2780 drivers/net/ppp/pptp.c:193
 pptp_xmit+0xc9a/0x2780 drivers/net/ppp/pptp.c:193
 ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2286 [inline]
 ppp_input+0x1d9/0xe60 drivers/net/ppp/ppp_generic.c:2310
 pppoe_rcv_core+0x166/0x6d0 drivers/net/ppp/pppoe.c:376
 sk_backlog_rcv+0x13f/0x420 include/net/sock.h:1148
 __release_sock+0x1d3/0x330 net/core/sock.c:3194
 release_sock+0x6b/0x270 net/core/sock.c:3748
 pppoe_sendmsg+0x15d/0xcb0 drivers/net/ppp/pppoe.c:904
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg+0x333/0x3d0 net/socket.c:729
 ____sys_sendmsg+0x893/0xd80 net/socket.c:2614
 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2668
 __sys_sendmmsg+0x2d9/0x7c0 net/socket.c:2757
 __do_sys_sendmmsg net/socket.c:2784 [inline]
 __se_sys_sendmmsg net/socket.c:2781 [inline]
 __x64_sys_sendmmsg+0xc6/0x150 net/socket.c:2781
 x64_sys_call+0x21de/0x3e20 arch/x86/include/generated/asm/syscalls_64.h:308
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:4186 [inline]
 slab_alloc_node mm/slub.c:4229 [inline]
 __do_kmalloc_node mm/slub.c:4364 [inline]
 __kmalloc_node_track_caller_noprof+0x96d/0x12f0 mm/slub.c:4384
 kmalloc_reserve+0x22f/0x4b0 net/core/skbuff.c:600
 pskb_expand_head+0x1fc/0x1610 net/core/skbuff.c:2240
 skb_realloc_headroom+0x152/0x2d0 net/core/skbuff.c:2320
 pptp_xmit+0xa0d/0x2780 drivers/net/ppp/pptp.c:181
 ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2286 [inline]
 ppp_input+0x1d9/0xe60 drivers/net/ppp/ppp_generic.c:2310
 pppoe_rcv_core+0x166/0x6d0 drivers/net/ppp/pppoe.c:376
 sk_backlog_rcv+0x13f/0x420 include/net/sock.h:1148
 __release_sock+0x1d3/0x330 net/core/sock.c:3194
 release_sock+0x6b/0x270 net/core/sock.c:3748
 pppoe_sendmsg+0x15d/0xcb0 drivers/net/ppp/pppoe.c:904
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg+0x333/0x3d0 net/socket.c:729
 ____sys_sendmsg+0x893/0xd80 net/socket.c:2614
 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2668
 __sys_sendmmsg+0x2d9/0x7c0 net/socket.c:2757
 __do_sys_sendmmsg net/socket.c:2784 [inline]
 __se_sys_sendmmsg net/socket.c:2781 [inline]
 __x64_sys_sendmmsg+0xc6/0x150 net/socket.c:2781
 x64_sys_call+0x21de/0x3e20 arch/x86/include/generated/asm/syscalls_64.h:308
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 1 UID: 0 PID: 6081 Comm: syz.0.29 Not tainted 6.16.0-syzkaller-10499-g89748acdf226 #0 PREEMPT(none) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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