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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
 __sk_receive_skb+0x562/0xac0 net/core/sock.c:579
 sk_receive_skb include/net/sock.h:1972 [inline]
 pppoe_rcv+0x9dd/0xcc0 drivers/net/ppp/pppoe.c:451
 __netif_receive_skb_one_core net/core/dev.c:5979 [inline]
 __netif_receive_skb+0x474/0xac0 net/core/dev.c:6092
 process_backlog+0x485/0xa00 net/core/dev.c:6444
 __napi_poll+0xdd/0x8a0 net/core/dev.c:7497
 napi_poll net/core/dev.c:7560 [inline]
 net_rx_action+0xa59/0x1ac0 net/core/dev.c:7687
 handle_softirqs+0x169/0x6e0 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0x66/0x180 kernel/softirq.c:680
 irq_exit_rcu+0x12/0x20 kernel/softirq.c:696
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0x84/0x90 arch/x86/kernel/apic/apic.c:1050
 asm_sysvec_apic_timer_interrupt+0x1f/0x30 arch/x86/include/asm/idtentry.h:702
 smap_restore arch/x86/include/asm/smap.h:53 [inline]
 get_shadow_origin_ptr mm/kmsan/instrumentation.c:39 [inline]
 __msan_metadata_ptr_for_load_8+0x2b/0x40 mm/kmsan/instrumentation.c:94
 set_pte_range+0x760/0xf10 mm/memory.c:5313
 filemap_map_order0_folio mm/filemap.c:3725 [inline]
 filemap_map_pages+0x1af9/0x3140 mm/filemap.c:3780
 do_fault_around mm/memory.c:5531 [inline]
 do_read_fault mm/memory.c:5564 [inline]
 do_fault mm/memory.c:5707 [inline]
 do_pte_missing mm/memory.c:4234 [inline]
 handle_pte_fault mm/memory.c:6052 [inline]
 __handle_mm_fault mm/memory.c:6195 [inline]
 handle_mm_fault+0x8aac/0xdf70 mm/memory.c:6364
 do_user_addr_fault+0x177d/0x2560 arch/x86/mm/fault.c:1336
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x68/0xb0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x2b/0x30 arch/x86/include/asm/idtentry.h:623

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
 __sk_receive_skb+0x562/0xac0 net/core/sock.c:579
 sk_receive_skb include/net/sock.h:1972 [inline]
 pppoe_rcv+0x9dd/0xcc0 drivers/net/ppp/pppoe.c:451
 __netif_receive_skb_one_core net/core/dev.c:5979 [inline]
 __netif_receive_skb+0x474/0xac0 net/core/dev.c:6092
 process_backlog+0x485/0xa00 net/core/dev.c:6444
 __napi_poll+0xdd/0x8a0 net/core/dev.c:7497
 napi_poll net/core/dev.c:7560 [inline]
 net_rx_action+0xa59/0x1ac0 net/core/dev.c:7687
 handle_softirqs+0x169/0x6e0 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0x66/0x180 kernel/softirq.c:680
 irq_exit_rcu+0x12/0x20 kernel/softirq.c:696
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0x84/0x90 arch/x86/kernel/apic/apic.c:1050
 asm_sysvec_apic_timer_interrupt+0x1f/0x30 arch/x86/include/asm/idtentry.h:702

CPU: 0 UID: 0 PID: 6505 Comm: syz.1.112 Not tainted 6.16.0-syzkaller-11129-geacf91b0c78a #0 PREEMPT(none) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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