linux-stable.git/drivers/net/ppp, branch v6.6.78 Linux kernel stable tree ppp: fix ppp_async_encode() illegal access 2024-10-17T13:24:30+00:00 Eric Dumazet edumazet@google.com 2024-10-09T18:58:02+00:00 8fe992ff3df493d1949922ca234419f3ede08dff [ Upstream commit 40dddd4b8bd08a69471efd96107a4e1c73fabefc ] syzbot reported an issue in ppp_async_encode() [1] In this case, pppoe_sendmsg() is called with a zero size. Then ppp_async_encode() is called with an empty skb. BUG: KMSAN: uninit-value in ppp_async_encode drivers/net/ppp/ppp_async.c:545 [inline] BUG: KMSAN: uninit-value in ppp_async_push+0xb4f/0x2660 drivers/net/ppp/ppp_async.c:675 ppp_async_encode drivers/net/ppp/ppp_async.c:545 [inline] ppp_async_push+0xb4f/0x2660 drivers/net/ppp/ppp_async.c:675 ppp_async_send+0x130/0x1b0 drivers/net/ppp/ppp_async.c:634 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:1113 __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:2602 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2656 __sys_sendmmsg+0x3c1/0x960 net/socket.c:2742 __do_sys_sendmmsg net/socket.c:2771 [inline] __se_sys_sendmmsg net/socket.c:2768 [inline] __x64_sys_sendmmsg+0xbc/0x120 net/socket.c:2768 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:4092 [inline] slab_alloc_node mm/slub.c:4135 [inline] kmem_cache_alloc_node_noprof+0x6bf/0xb80 mm/slub.c:4187 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:2602 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2656 __sys_sendmmsg+0x3c1/0x960 net/socket.c:2742 __do_sys_sendmmsg net/socket.c:2771 [inline] __se_sys_sendmmsg net/socket.c:2768 [inline] __x64_sys_sendmmsg+0xbc/0x120 net/socket.c:2768 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: 1 UID: 0 PID: 5411 Comm: syz.1.14 Not tainted 6.12.0-rc1-syzkaller-00165-g360c1f1f24c6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot+1d121645899e7692f92a@syzkaller.appspotmail.com Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20241009185802.3763282-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 40dddd4b8bd08a69471efd96107a4e1c73fabefc ]

syzbot reported an issue in ppp_async_encode() [1]

In this case, pppoe_sendmsg() is called with a zero size.
Then ppp_async_encode() is called with an empty skb.

BUG: KMSAN: uninit-value in ppp_async_encode drivers/net/ppp/ppp_async.c:545 [inline]
 BUG: KMSAN: uninit-value in ppp_async_push+0xb4f/0x2660 drivers/net/ppp/ppp_async.c:675
  ppp_async_encode drivers/net/ppp/ppp_async.c:545 [inline]
  ppp_async_push+0xb4f/0x2660 drivers/net/ppp/ppp_async.c:675
  ppp_async_send+0x130/0x1b0 drivers/net/ppp/ppp_async.c:634
  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:1113
  __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:2602
  ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2656
  __sys_sendmmsg+0x3c1/0x960 net/socket.c:2742
  __do_sys_sendmmsg net/socket.c:2771 [inline]
  __se_sys_sendmmsg net/socket.c:2768 [inline]
  __x64_sys_sendmmsg+0xbc/0x120 net/socket.c:2768
  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:4092 [inline]
  slab_alloc_node mm/slub.c:4135 [inline]
  kmem_cache_alloc_node_noprof+0x6bf/0xb80 mm/slub.c:4187
  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:2602
  ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2656
  __sys_sendmmsg+0x3c1/0x960 net/socket.c:2742
  __do_sys_sendmmsg net/socket.c:2771 [inline]
  __se_sys_sendmmsg net/socket.c:2768 [inline]
  __x64_sys_sendmmsg+0xbc/0x120 net/socket.c:2768
  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: 1 UID: 0 PID: 5411 Comm: syz.1.14 Not tainted 6.12.0-rc1-syzkaller-00165-g360c1f1f24c6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzbot+1d121645899e7692f92a@syzkaller.appspotmail.com
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20241009185802.3763282-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ppp: do not assume bh is held in ppp_channel_bridge_input() 2024-10-10T09:57:18+00:00 Eric Dumazet edumazet@google.com 2024-09-27T07:45:53+00:00 f9620e2a665aa642625bd2501282bbddff556bd7 [ Upstream commit aec7291003df78cb71fd461d7b672912bde55807 ] Networking receive path is usually handled from BH handler. However, some protocols need to acquire the socket lock, and packets might be stored in the socket backlog is the socket was owned by a user process. In this case, release_sock(), __release_sock(), and sk_backlog_rcv() might call the sk->sk_backlog_rcv() handler in process context. sybot caught ppp was not considering this case in ppp_channel_bridge_input() : WARNING: inconsistent lock state 6.11.0-rc7-syzkaller-g5f5673607153 #0 Not tainted -------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. ksoftirqd/1/24 [HC0[0]:SC1[1]:HE1:SE0] takes: ffff0000db7f11e0 (&pch->downl){+.?.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff0000db7f11e0 (&pch->downl){+.?.}-{2:2}, at: ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2272 [inline] ffff0000db7f11e0 (&pch->downl){+.?.}-{2:2}, at: ppp_input+0x16c/0x854 drivers/net/ppp/ppp_generic.c:2304 {SOFTIRQ-ON-W} state was registered at: lock_acquire+0x240/0x728 kernel/locking/lockdep.c:5759 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x48/0x60 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2272 [inline] ppp_input+0x16c/0x854 drivers/net/ppp/ppp_generic.c:2304 pppoe_rcv_core+0xfc/0x314 drivers/net/ppp/pppoe.c:379 sk_backlog_rcv include/net/sock.h:1111 [inline] __release_sock+0x1a8/0x3d8 net/core/sock.c:3004 release_sock+0x68/0x1b8 net/core/sock.c:3558 pppoe_sendmsg+0xc8/0x5d8 drivers/net/ppp/pppoe.c:903 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x374/0x4f4 net/socket.c:2204 __do_sys_sendto net/socket.c:2216 [inline] __se_sys_sendto net/socket.c:2212 [inline] __arm64_sys_sendto+0xd8/0xf8 net/socket.c:2212 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598 irq event stamp: 282914 hardirqs last enabled at (282914): [<ffff80008b42e30c>] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline] hardirqs last enabled at (282914): [<ffff80008b42e30c>] _raw_spin_unlock_irqrestore+0x38/0x98 kernel/locking/spinlock.c:194 hardirqs last disabled at (282913): [<ffff80008b42e13c>] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline] hardirqs last disabled at (282913): [<ffff80008b42e13c>] _raw_spin_lock_irqsave+0x2c/0x7c kernel/locking/spinlock.c:162 softirqs last enabled at (282904): [<ffff8000801f8e88>] softirq_handle_end kernel/softirq.c:400 [inline] softirqs last enabled at (282904): [<ffff8000801f8e88>] handle_softirqs+0xa3c/0xbfc kernel/softirq.c:582 softirqs last disabled at (282909): [<ffff8000801fbdf8>] run_ksoftirqd+0x70/0x158 kernel/softirq.c:928 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&pch->downl); <Interrupt> lock(&pch->downl); *** DEADLOCK *** 1 lock held by ksoftirqd/1/24: #0: ffff80008f74dfa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:325 stack backtrace: CPU: 1 UID: 0 PID: 24 Comm: ksoftirqd/1 Not tainted 6.11.0-rc7-syzkaller-g5f5673607153 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call trace: dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:319 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:326 __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:119 dump_stack+0x1c/0x28 lib/dump_stack.c:128 print_usage_bug+0x698/0x9ac kernel/locking/lockdep.c:4000 mark_lock_irq+0x980/0xd2c mark_lock+0x258/0x360 kernel/locking/lockdep.c:4677 __lock_acquire+0xf48/0x779c kernel/locking/lockdep.c:5096 lock_acquire+0x240/0x728 kernel/locking/lockdep.c:5759 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x48/0x60 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2272 [inline] ppp_input+0x16c/0x854 drivers/net/ppp/ppp_generic.c:2304 ppp_async_process+0x98/0x150 drivers/net/ppp/ppp_async.c:495 tasklet_action_common+0x318/0x3f4 kernel/softirq.c:785 tasklet_action+0x68/0x8c kernel/softirq.c:811 handle_softirqs+0x2e4/0xbfc kernel/softirq.c:554 run_ksoftirqd+0x70/0x158 kernel/softirq.c:928 smpboot_thread_fn+0x4b0/0x90c kernel/smpboot.c:164 kthread+0x288/0x310 kernel/kthread.c:389 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860 Fixes: 4cf476ced45d ("ppp: add PPPIOCBRIDGECHAN and PPPIOCUNBRIDGECHAN ioctls") Reported-by: syzbot+bd8d55ee2acd0a71d8ce@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/66f661e2.050a0220.38ace9.000f.GAE@google.com/T/#u Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Tom Parkin <tparkin@katalix.com> Cc: James Chapman <jchapman@katalix.com> Link: https://patch.msgid.link/20240927074553.341910-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit aec7291003df78cb71fd461d7b672912bde55807 ]

Networking receive path is usually handled from BH handler.
However, some protocols need to acquire the socket lock, and
packets might be stored in the socket backlog is the socket was
owned by a user process.

In this case, release_sock(), __release_sock(), and sk_backlog_rcv()
might call the sk->sk_backlog_rcv() handler in process context.

sybot caught ppp was not considering this case in
ppp_channel_bridge_input() :

WARNING: inconsistent lock state
6.11.0-rc7-syzkaller-g5f5673607153 #0 Not tainted
--------------------------------
inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
ksoftirqd/1/24 [HC0[0]:SC1[1]:HE1:SE0] takes:
 ffff0000db7f11e0 (&pch->downl){+.?.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
 ffff0000db7f11e0 (&pch->downl){+.?.}-{2:2}, at: ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2272 [inline]
 ffff0000db7f11e0 (&pch->downl){+.?.}-{2:2}, at: ppp_input+0x16c/0x854 drivers/net/ppp/ppp_generic.c:2304
{SOFTIRQ-ON-W} state was registered at:
   lock_acquire+0x240/0x728 kernel/locking/lockdep.c:5759
   __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
   _raw_spin_lock+0x48/0x60 kernel/locking/spinlock.c:154
   spin_lock include/linux/spinlock.h:351 [inline]
   ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2272 [inline]
   ppp_input+0x16c/0x854 drivers/net/ppp/ppp_generic.c:2304
   pppoe_rcv_core+0xfc/0x314 drivers/net/ppp/pppoe.c:379
   sk_backlog_rcv include/net/sock.h:1111 [inline]
   __release_sock+0x1a8/0x3d8 net/core/sock.c:3004
   release_sock+0x68/0x1b8 net/core/sock.c:3558
   pppoe_sendmsg+0xc8/0x5d8 drivers/net/ppp/pppoe.c:903
   sock_sendmsg_nosec net/socket.c:730 [inline]
   __sock_sendmsg net/socket.c:745 [inline]
   __sys_sendto+0x374/0x4f4 net/socket.c:2204
   __do_sys_sendto net/socket.c:2216 [inline]
   __se_sys_sendto net/socket.c:2212 [inline]
   __arm64_sys_sendto+0xd8/0xf8 net/socket.c:2212
   __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
   invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
   el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
   do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
   el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712
   el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730
   el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598
irq event stamp: 282914
 hardirqs last  enabled at (282914): [<ffff80008b42e30c>] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
 hardirqs last  enabled at (282914): [<ffff80008b42e30c>] _raw_spin_unlock_irqrestore+0x38/0x98 kernel/locking/spinlock.c:194
 hardirqs last disabled at (282913): [<ffff80008b42e13c>] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline]
 hardirqs last disabled at (282913): [<ffff80008b42e13c>] _raw_spin_lock_irqsave+0x2c/0x7c kernel/locking/spinlock.c:162
 softirqs last  enabled at (282904): [<ffff8000801f8e88>] softirq_handle_end kernel/softirq.c:400 [inline]
 softirqs last  enabled at (282904): [<ffff8000801f8e88>] handle_softirqs+0xa3c/0xbfc kernel/softirq.c:582
 softirqs last disabled at (282909): [<ffff8000801fbdf8>] run_ksoftirqd+0x70/0x158 kernel/softirq.c:928

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&pch->downl);
  <Interrupt>
    lock(&pch->downl);

 *** DEADLOCK ***

1 lock held by ksoftirqd/1/24:
  #0: ffff80008f74dfa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:325

stack backtrace:
CPU: 1 UID: 0 PID: 24 Comm: ksoftirqd/1 Not tainted 6.11.0-rc7-syzkaller-g5f5673607153 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Call trace:
  dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:319
  show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:326
  __dump_stack lib/dump_stack.c:93 [inline]
  dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:119
  dump_stack+0x1c/0x28 lib/dump_stack.c:128
  print_usage_bug+0x698/0x9ac kernel/locking/lockdep.c:4000
 mark_lock_irq+0x980/0xd2c
  mark_lock+0x258/0x360 kernel/locking/lockdep.c:4677
  __lock_acquire+0xf48/0x779c kernel/locking/lockdep.c:5096
  lock_acquire+0x240/0x728 kernel/locking/lockdep.c:5759
  __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
  _raw_spin_lock+0x48/0x60 kernel/locking/spinlock.c:154
  spin_lock include/linux/spinlock.h:351 [inline]
  ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2272 [inline]
  ppp_input+0x16c/0x854 drivers/net/ppp/ppp_generic.c:2304
  ppp_async_process+0x98/0x150 drivers/net/ppp/ppp_async.c:495
  tasklet_action_common+0x318/0x3f4 kernel/softirq.c:785
  tasklet_action+0x68/0x8c kernel/softirq.c:811
  handle_softirqs+0x2e4/0xbfc kernel/softirq.c:554
  run_ksoftirqd+0x70/0x158 kernel/softirq.c:928
  smpboot_thread_fn+0x4b0/0x90c kernel/smpboot.c:164
  kthread+0x288/0x310 kernel/kthread.c:389
  ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860

Fixes: 4cf476ced45d ("ppp: add PPPIOCBRIDGECHAN and PPPIOCUNBRIDGECHAN ioctls")
Reported-by: syzbot+bd8d55ee2acd0a71d8ce@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/66f661e2.050a0220.38ace9.000f.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tom Parkin <tparkin@katalix.com>
Cc: James Chapman <jchapman@katalix.com>
Link: https://patch.msgid.link/20240927074553.341910-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
pppoe: Fix memory leak in pppoe_sendmsg() 2024-08-19T04:04:27+00:00 Gavrilov Ilia Ilia.Gavrilov@infotecs.ru 2024-02-14T09:01:50+00:00 5fbbd952e7c395eb6cf7fbc617888874740906bf [ Upstream commit dc34ebd5c018b0edf47f39d11083ad8312733034 ] syzbot reports a memory leak in pppoe_sendmsg [1]. The problem is in the pppoe_recvmsg() function that handles errors in the wrong order. For the skb_recv_datagram() function, check the pointer to skb for NULL first, and then check the 'error' variable, because the skb_recv_datagram() function can set 'error' to -EAGAIN in a loop but return a correct pointer to socket buffer after a number of attempts, though 'error' remains set to -EAGAIN. skb_recv_datagram __skb_recv_datagram // Loop. if (err == -EAGAIN) then // go to the next loop iteration __skb_try_recv_datagram // if (skb != NULL) then return 'skb' // else if a signal is received then // return -EAGAIN Found by InfoTeCS on behalf of Linux Verification Center (linuxtesting.org) with Syzkaller. Link: https://syzkaller.appspot.com/bug?extid=6bdfd184eac7709e5cc9 [1] Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot+6bdfd184eac7709e5cc9@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=6bdfd184eac7709e5cc9 Signed-off-by: Gavrilov Ilia <Ilia.Gavrilov@infotecs.ru> Reviewed-by: Guillaume Nault <gnault@redhat.com> Link: https://lore.kernel.org/r/20240214085814.3894917-1-Ilia.Gavrilov@infotecs.ru Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit dc34ebd5c018b0edf47f39d11083ad8312733034 ]

syzbot reports a memory leak in pppoe_sendmsg [1].

The problem is in the pppoe_recvmsg() function that handles errors
in the wrong order. For the skb_recv_datagram() function, check
the pointer to skb for NULL first, and then check the 'error' variable,
because the skb_recv_datagram() function can set 'error'
to -EAGAIN in a loop but return a correct pointer to socket buffer
after a number of attempts, though 'error' remains set to -EAGAIN.

skb_recv_datagram
      __skb_recv_datagram          // Loop. if (err == -EAGAIN) then
                                   // go to the next loop iteration
          __skb_try_recv_datagram  // if (skb != NULL) then return 'skb'
                                   // else if a signal is received then
                                   // return -EAGAIN

Found by InfoTeCS on behalf of Linux Verification Center
(linuxtesting.org) with Syzkaller.

Link: https://syzkaller.appspot.com/bug?extid=6bdfd184eac7709e5cc9 [1]

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzbot+6bdfd184eac7709e5cc9@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=6bdfd184eac7709e5cc9
Signed-off-by: Gavrilov Ilia <Ilia.Gavrilov@infotecs.ru>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Link: https://lore.kernel.org/r/20240214085814.3894917-1-Ilia.Gavrilov@infotecs.ru
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ppp: reject claimed-as-LCP but actually malformed packets 2024-07-18T11:21:14+00:00 Dmitry Antipov dmantipov@yandex.ru 2024-07-08T11:56:15+00:00 099502ca410922b56353ccef2749bc0de669da78 [ Upstream commit f2aeb7306a898e1cbd03963d376f4b6656ca2b55 ] Since 'ppp_async_encode()' assumes valid LCP packets (with code from 1 to 7 inclusive), add 'ppp_check_packet()' to ensure that LCP packet has an actual body beyond PPP_LCP header bytes, and reject claimed-as-LCP but actually malformed data otherwise. Reported-by: syzbot+ec0723ba9605678b14bf@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=ec0723ba9605678b14bf Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit f2aeb7306a898e1cbd03963d376f4b6656ca2b55 ]

Since 'ppp_async_encode()' assumes valid LCP packets (with code
from 1 to 7 inclusive), add 'ppp_check_packet()' to ensure that
LCP packet has an actual body beyond PPP_LCP header bytes, and
reject claimed-as-LCP but actually malformed data otherwise.

Reported-by: syzbot+ec0723ba9605678b14bf@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=ec0723ba9605678b14bf
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ppp_async: limit MRU to 64K 2024-02-16T18:10:50+00:00 Eric Dumazet edumazet@google.com 2024-02-05T17:10:04+00:00 7e5ef49670766c9742ffcd9cead7cdb018268719 [ Upstream commit cb88cb53badb8aeb3955ad6ce80b07b598e310b8 ] syzbot triggered a warning [1] in __alloc_pages(): WARN_ON_ONCE_GFP(order > MAX_PAGE_ORDER, gfp) Willem fixed a similar issue in commit c0a2a1b0d631 ("ppp: limit MRU to 64K") Adopt the same sanity check for ppp_async_ioctl(PPPIOCSMRU) [1]: WARNING: CPU: 1 PID: 11 at mm/page_alloc.c:4543 __alloc_pages+0x308/0x698 mm/page_alloc.c:4543 Modules linked in: CPU: 1 PID: 11 Comm: kworker/u4:0 Not tainted 6.8.0-rc2-syzkaller-g41bccc98fb79 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Workqueue: events_unbound flush_to_ldisc pstate: 204000c5 (nzCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : __alloc_pages+0x308/0x698 mm/page_alloc.c:4543 lr : __alloc_pages+0xc8/0x698 mm/page_alloc.c:4537 sp : ffff800093967580 x29: ffff800093967660 x28: ffff8000939675a0 x27: dfff800000000000 x26: ffff70001272ceb4 x25: 0000000000000000 x24: ffff8000939675c0 x23: 0000000000000000 x22: 0000000000060820 x21: 1ffff0001272ceb8 x20: ffff8000939675e0 x19: 0000000000000010 x18: ffff800093967120 x17: ffff800083bded5c x16: ffff80008ac97500 x15: 0000000000000005 x14: 1ffff0001272cebc x13: 0000000000000000 x12: 0000000000000000 x11: ffff70001272cec1 x10: 1ffff0001272cec0 x9 : 0000000000000001 x8 : ffff800091c91000 x7 : 0000000000000000 x6 : 000000000000003f x5 : 00000000ffffffff x4 : 0000000000000000 x3 : 0000000000000020 x2 : 0000000000000008 x1 : 0000000000000000 x0 : ffff8000939675e0 Call trace: __alloc_pages+0x308/0x698 mm/page_alloc.c:4543 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] __kmalloc_large_node+0xbc/0x1fc mm/slub.c:3926 __do_kmalloc_node mm/slub.c:3969 [inline] __kmalloc_node_track_caller+0x418/0x620 mm/slub.c:4001 kmalloc_reserve+0x17c/0x23c net/core/skbuff.c:590 __alloc_skb+0x1c8/0x3d8 net/core/skbuff.c:651 __netdev_alloc_skb+0xb8/0x3e8 net/core/skbuff.c:715 netdev_alloc_skb include/linux/skbuff.h:3235 [inline] dev_alloc_skb include/linux/skbuff.h:3248 [inline] ppp_async_input drivers/net/ppp/ppp_async.c:863 [inline] ppp_asynctty_receive+0x588/0x186c drivers/net/ppp/ppp_async.c:341 tty_ldisc_receive_buf+0x12c/0x15c drivers/tty/tty_buffer.c:390 tty_port_default_receive_buf+0x74/0xac drivers/tty/tty_port.c:37 receive_buf drivers/tty/tty_buffer.c:444 [inline] flush_to_ldisc+0x284/0x6e4 drivers/tty/tty_buffer.c:494 process_one_work+0x694/0x1204 kernel/workqueue.c:2633 process_scheduled_works kernel/workqueue.c:2706 [inline] worker_thread+0x938/0xef4 kernel/workqueue.c:2787 kthread+0x288/0x310 kernel/kthread.c:388 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-and-tested-by: syzbot+c5da1f087c9e4ec6c933@syzkaller.appspotmail.com Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://lore.kernel.org/r/20240205171004.1059724-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit cb88cb53badb8aeb3955ad6ce80b07b598e310b8 ]

syzbot triggered a warning [1] in __alloc_pages():

WARN_ON_ONCE_GFP(order > MAX_PAGE_ORDER, gfp)

Willem fixed a similar issue in commit c0a2a1b0d631 ("ppp: limit MRU to 64K")

Adopt the same sanity check for ppp_async_ioctl(PPPIOCSMRU)

[1]:

 WARNING: CPU: 1 PID: 11 at mm/page_alloc.c:4543 __alloc_pages+0x308/0x698 mm/page_alloc.c:4543
Modules linked in:
CPU: 1 PID: 11 Comm: kworker/u4:0 Not tainted 6.8.0-rc2-syzkaller-g41bccc98fb79 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
Workqueue: events_unbound flush_to_ldisc
pstate: 204000c5 (nzCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 pc : __alloc_pages+0x308/0x698 mm/page_alloc.c:4543
 lr : __alloc_pages+0xc8/0x698 mm/page_alloc.c:4537
sp : ffff800093967580
x29: ffff800093967660 x28: ffff8000939675a0 x27: dfff800000000000
x26: ffff70001272ceb4 x25: 0000000000000000 x24: ffff8000939675c0
x23: 0000000000000000 x22: 0000000000060820 x21: 1ffff0001272ceb8
x20: ffff8000939675e0 x19: 0000000000000010 x18: ffff800093967120
x17: ffff800083bded5c x16: ffff80008ac97500 x15: 0000000000000005
x14: 1ffff0001272cebc x13: 0000000000000000 x12: 0000000000000000
x11: ffff70001272cec1 x10: 1ffff0001272cec0 x9 : 0000000000000001
x8 : ffff800091c91000 x7 : 0000000000000000 x6 : 000000000000003f
x5 : 00000000ffffffff x4 : 0000000000000000 x3 : 0000000000000020
x2 : 0000000000000008 x1 : 0000000000000000 x0 : ffff8000939675e0
Call trace:
  __alloc_pages+0x308/0x698 mm/page_alloc.c:4543
  __alloc_pages_node include/linux/gfp.h:238 [inline]
  alloc_pages_node include/linux/gfp.h:261 [inline]
  __kmalloc_large_node+0xbc/0x1fc mm/slub.c:3926
  __do_kmalloc_node mm/slub.c:3969 [inline]
  __kmalloc_node_track_caller+0x418/0x620 mm/slub.c:4001
  kmalloc_reserve+0x17c/0x23c net/core/skbuff.c:590
  __alloc_skb+0x1c8/0x3d8 net/core/skbuff.c:651
  __netdev_alloc_skb+0xb8/0x3e8 net/core/skbuff.c:715
  netdev_alloc_skb include/linux/skbuff.h:3235 [inline]
  dev_alloc_skb include/linux/skbuff.h:3248 [inline]
  ppp_async_input drivers/net/ppp/ppp_async.c:863 [inline]
  ppp_asynctty_receive+0x588/0x186c drivers/net/ppp/ppp_async.c:341
  tty_ldisc_receive_buf+0x12c/0x15c drivers/tty/tty_buffer.c:390
  tty_port_default_receive_buf+0x74/0xac drivers/tty/tty_port.c:37
  receive_buf drivers/tty/tty_buffer.c:444 [inline]
  flush_to_ldisc+0x284/0x6e4 drivers/tty/tty_buffer.c:494
  process_one_work+0x694/0x1204 kernel/workqueue.c:2633
  process_scheduled_works kernel/workqueue.c:2706 [inline]
  worker_thread+0x938/0xef4 kernel/workqueue.c:2787
  kthread+0x288/0x310 kernel/kthread.c:388
  ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-and-tested-by: syzbot+c5da1f087c9e4ec6c933@syzkaller.appspotmail.com
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20240205171004.1059724-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ppp: limit MRU to 64K 2023-11-28T17:19:51+00:00 Willem de Bruijn willemb@google.com 2023-11-13T03:16:32+00:00 0735ea00b2711f49bc79d5705b2e1e006a32a056 [ Upstream commit c0a2a1b0d631fc460d830f52d06211838874d655 ] ppp_sync_ioctl allows setting device MRU, but does not sanity check this input. Limit to a sane upper bound of 64KB. No implementation I could find generates larger than 64KB frames. RFC 2823 mentions an upper bound of PPP over SDL of 64KB based on the 16-bit length field. Other protocols will be smaller, such as PPPoE (9KB jumbo frame) and PPPoA (18190 maximum CPCS-SDU size, RFC 2364). PPTP and L2TP encapsulate in IP. Syzbot managed to trigger alloc warning in __alloc_pages: if (WARN_ON_ONCE_GFP(order > MAX_ORDER, gfp)) WARNING: CPU: 1 PID: 37 at mm/page_alloc.c:4544 __alloc_pages+0x3ab/0x4a0 mm/page_alloc.c:4544 __alloc_skb+0x12b/0x330 net/core/skbuff.c:651 __netdev_alloc_skb+0x72/0x3f0 net/core/skbuff.c:715 netdev_alloc_skb include/linux/skbuff.h:3225 [inline] dev_alloc_skb include/linux/skbuff.h:3238 [inline] ppp_sync_input drivers/net/ppp/ppp_synctty.c:669 [inline] ppp_sync_receive+0xff/0x680 drivers/net/ppp/ppp_synctty.c:334 tty_ldisc_receive_buf+0x14c/0x180 drivers/tty/tty_buffer.c:390 tty_port_default_receive_buf+0x70/0xb0 drivers/tty/tty_port.c:37 receive_buf drivers/tty/tty_buffer.c:444 [inline] flush_to_ldisc+0x261/0x780 drivers/tty/tty_buffer.c:494 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630 With call ioctl$PPPIOCSMRU1(r1, 0x40047452, &(0x7f0000000100)=0x5e6417a8) Similar code exists in other drivers that implement ppp_channel_ops ioctl PPPIOCSMRU. Those might also be in scope. Notably excluded from this are pppol2tp_ioctl and pppoe_ioctl. This code goes back to the start of git history. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot+6177e1f90d92583bcc58@syzkaller.appspotmail.com Signed-off-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit c0a2a1b0d631fc460d830f52d06211838874d655 ]

ppp_sync_ioctl allows setting device MRU, but does not sanity check
this input.

Limit to a sane upper bound of 64KB.

No implementation I could find generates larger than 64KB frames.
RFC 2823 mentions an upper bound of PPP over SDL of 64KB based on the
16-bit length field. Other protocols will be smaller, such as PPPoE
(9KB jumbo frame) and PPPoA (18190 maximum CPCS-SDU size, RFC 2364).
PPTP and L2TP encapsulate in IP.

Syzbot managed to trigger alloc warning in __alloc_pages:

	if (WARN_ON_ONCE_GFP(order > MAX_ORDER, gfp))

    WARNING: CPU: 1 PID: 37 at mm/page_alloc.c:4544 __alloc_pages+0x3ab/0x4a0 mm/page_alloc.c:4544

    __alloc_skb+0x12b/0x330 net/core/skbuff.c:651
    __netdev_alloc_skb+0x72/0x3f0 net/core/skbuff.c:715
    netdev_alloc_skb include/linux/skbuff.h:3225 [inline]
    dev_alloc_skb include/linux/skbuff.h:3238 [inline]
    ppp_sync_input drivers/net/ppp/ppp_synctty.c:669 [inline]
    ppp_sync_receive+0xff/0x680 drivers/net/ppp/ppp_synctty.c:334
    tty_ldisc_receive_buf+0x14c/0x180 drivers/tty/tty_buffer.c:390
    tty_port_default_receive_buf+0x70/0xb0 drivers/tty/tty_port.c:37
    receive_buf drivers/tty/tty_buffer.c:444 [inline]
    flush_to_ldisc+0x261/0x780 drivers/tty/tty_buffer.c:494
    process_one_work+0x884/0x15c0 kernel/workqueue.c:2630

With call

    ioctl$PPPIOCSMRU1(r1, 0x40047452, &(0x7f0000000100)=0x5e6417a8)

Similar code exists in other drivers that implement ppp_channel_ops
ioctl PPPIOCSMRU. Those might also be in scope. Notably excluded from
this are pppol2tp_ioctl and pppoe_ioctl.

This code goes back to the start of git history.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzbot+6177e1f90d92583bcc58@syzkaller.appspotmail.com
Signed-off-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
tty: Fix uninit-value access in ppp_sync_receive() 2023-11-28T17:19:50+00:00 Shigeru Yoshida syoshida@redhat.com 2023-11-08T15:44:20+00:00 30007a74cb41d75ce926fcef52bbbd074e116336 [ Upstream commit 719639853d88071dfdfd8d9971eca9c283ff314c ] KMSAN reported the following uninit-value access issue: ===================================================== BUG: KMSAN: uninit-value in ppp_sync_input drivers/net/ppp/ppp_synctty.c:690 [inline] BUG: KMSAN: uninit-value in ppp_sync_receive+0xdc9/0xe70 drivers/net/ppp/ppp_synctty.c:334 ppp_sync_input drivers/net/ppp/ppp_synctty.c:690 [inline] ppp_sync_receive+0xdc9/0xe70 drivers/net/ppp/ppp_synctty.c:334 tiocsti+0x328/0x450 drivers/tty/tty_io.c:2295 tty_ioctl+0x808/0x1920 drivers/tty/tty_io.c:2694 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0x211/0x400 fs/ioctl.c:857 __x64_sys_ioctl+0x97/0xe0 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b Uninit was created at: __alloc_pages+0x75d/0xe80 mm/page_alloc.c:4591 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] __page_frag_cache_refill+0x9a/0x2c0 mm/page_alloc.c:4691 page_frag_alloc_align+0x91/0x5d0 mm/page_alloc.c:4722 page_frag_alloc include/linux/gfp.h:322 [inline] __netdev_alloc_skb+0x215/0x6d0 net/core/skbuff.c:728 netdev_alloc_skb include/linux/skbuff.h:3225 [inline] dev_alloc_skb include/linux/skbuff.h:3238 [inline] ppp_sync_input drivers/net/ppp/ppp_synctty.c:669 [inline] ppp_sync_receive+0x237/0xe70 drivers/net/ppp/ppp_synctty.c:334 tiocsti+0x328/0x450 drivers/tty/tty_io.c:2295 tty_ioctl+0x808/0x1920 drivers/tty/tty_io.c:2694 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0x211/0x400 fs/ioctl.c:857 __x64_sys_ioctl+0x97/0xe0 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b CPU: 0 PID: 12950 Comm: syz-executor.1 Not tainted 6.6.0-14500-g1c41041124bd #10 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc38 04/01/2014 ===================================================== ppp_sync_input() checks the first 2 bytes of the data are PPP_ALLSTATIONS and PPP_UI. However, if the data length is 1 and the first byte is PPP_ALLSTATIONS, an access to an uninitialized value occurs when checking PPP_UI. This patch resolves this issue by checking the data length. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Shigeru Yoshida <syoshida@redhat.com> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 719639853d88071dfdfd8d9971eca9c283ff314c ]

KMSAN reported the following uninit-value access issue:

=====================================================
BUG: KMSAN: uninit-value in ppp_sync_input drivers/net/ppp/ppp_synctty.c:690 [inline]
BUG: KMSAN: uninit-value in ppp_sync_receive+0xdc9/0xe70 drivers/net/ppp/ppp_synctty.c:334
 ppp_sync_input drivers/net/ppp/ppp_synctty.c:690 [inline]
 ppp_sync_receive+0xdc9/0xe70 drivers/net/ppp/ppp_synctty.c:334
 tiocsti+0x328/0x450 drivers/tty/tty_io.c:2295
 tty_ioctl+0x808/0x1920 drivers/tty/tty_io.c:2694
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl+0x211/0x400 fs/ioctl.c:857
 __x64_sys_ioctl+0x97/0xe0 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

Uninit was created at:
 __alloc_pages+0x75d/0xe80 mm/page_alloc.c:4591
 __alloc_pages_node include/linux/gfp.h:238 [inline]
 alloc_pages_node include/linux/gfp.h:261 [inline]
 __page_frag_cache_refill+0x9a/0x2c0 mm/page_alloc.c:4691
 page_frag_alloc_align+0x91/0x5d0 mm/page_alloc.c:4722
 page_frag_alloc include/linux/gfp.h:322 [inline]
 __netdev_alloc_skb+0x215/0x6d0 net/core/skbuff.c:728
 netdev_alloc_skb include/linux/skbuff.h:3225 [inline]
 dev_alloc_skb include/linux/skbuff.h:3238 [inline]
 ppp_sync_input drivers/net/ppp/ppp_synctty.c:669 [inline]
 ppp_sync_receive+0x237/0xe70 drivers/net/ppp/ppp_synctty.c:334
 tiocsti+0x328/0x450 drivers/tty/tty_io.c:2295
 tty_ioctl+0x808/0x1920 drivers/tty/tty_io.c:2694
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl+0x211/0x400 fs/ioctl.c:857
 __x64_sys_ioctl+0x97/0xe0 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

CPU: 0 PID: 12950 Comm: syz-executor.1 Not tainted 6.6.0-14500-g1c41041124bd #10
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc38 04/01/2014
=====================================================

ppp_sync_input() checks the first 2 bytes of the data are PPP_ALLSTATIONS
and PPP_UI. However, if the data length is 1 and the first byte is
PPP_ALLSTATIONS, an access to an uninitialized value occurs when checking
PPP_UI. This patch resolves this issue by checking the data length.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Shigeru Yoshida <syoshida@redhat.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Merge tag 'tty-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty 2023-09-01T16:38:00+00:00 Linus Torvalds torvalds@linux-foundation.org 2023-09-01T16:38:00+00:00 8e1e49550dc85694abd04d86a8ee36bc98bd8b9e Pull tty/serial driver updates from Greg KH: "Here is the big set of tty and serial driver changes for 6.6-rc1. Lots of cleanups in here this cycle, and some driver updates. Short summary is: - Jiri's continued work to make the tty code and apis be a bit more sane with regards to modern kernel coding style and types - cpm_uart driver updates - n_gsm updates and fixes - meson driver updates - sc16is7xx driver updates - 8250 driver updates for different hardware types - qcom-geni driver fixes - tegra serial driver change - stm32 driver updates - synclink_gt driver cleanups - tty structure size reduction All of these have been in linux-next this week with no reported issues. The last bit of cleanups from Jiri and the tty structure size reduction came in last week, a bit late but as they were just style changes and size reductions, I figured they should get into this merge cycle so that others can work on top of them with no merge conflicts" * tag 'tty-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (199 commits) tty: shrink the size of struct tty_struct by 40 bytes tty: n_tty: deduplicate copy code in n_tty_receive_buf_real_raw() tty: n_tty: extract ECHO_OP processing to a separate function tty: n_tty: unify counts to size_t tty: n_tty: use u8 for chars and flags tty: n_tty: simplify chars_in_buffer() tty: n_tty: remove unsigned char casts from character constants tty: n_tty: move newline handling to a separate function tty: n_tty: move canon handling to a separate function tty: n_tty: use MASK() for masking out size bits tty: n_tty: make n_tty_data::num_overrun unsigned tty: n_tty: use time_is_before_jiffies() in n_tty_receive_overrun() tty: n_tty: use 'num' for writes' counts tty: n_tty: use output character directly tty: n_tty: make flow of n_tty_receive_buf_common() a bool Revert "tty: serial: meson: Add a earlycon for the T7 SoC" Documentation: devices.txt: Fix minors for ttyCPM* Documentation: devices.txt: Remove ttySIOC* Documentation: devices.txt: Remove ttyIOC* serial: 8250_bcm7271: improve bcm7271 8250 port ... 
Pull tty/serial driver updates from Greg KH:
 "Here is the big set of tty and serial driver changes for 6.6-rc1.

  Lots of cleanups in here this cycle, and some driver updates. Short
  summary is:

   - Jiri's continued work to make the tty code and apis be a bit more
     sane with regards to modern kernel coding style and types

   - cpm_uart driver updates

   - n_gsm updates and fixes

   - meson driver updates

   - sc16is7xx driver updates

   - 8250 driver updates for different hardware types

   - qcom-geni driver fixes

   - tegra serial driver change

   - stm32 driver updates

   - synclink_gt driver cleanups

   - tty structure size reduction

  All of these have been in linux-next this week with no reported
  issues. The last bit of cleanups from Jiri and the tty structure size
  reduction came in last week, a bit late but as they were just style
  changes and size reductions, I figured they should get into this merge
  cycle so that others can work on top of them with no merge conflicts"

* tag 'tty-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (199 commits)
  tty: shrink the size of struct tty_struct by 40 bytes
  tty: n_tty: deduplicate copy code in n_tty_receive_buf_real_raw()
  tty: n_tty: extract ECHO_OP processing to a separate function
  tty: n_tty: unify counts to size_t
  tty: n_tty: use u8 for chars and flags
  tty: n_tty: simplify chars_in_buffer()
  tty: n_tty: remove unsigned char casts from character constants
  tty: n_tty: move newline handling to a separate function
  tty: n_tty: move canon handling to a separate function
  tty: n_tty: use MASK() for masking out size bits
  tty: n_tty: make n_tty_data::num_overrun unsigned
  tty: n_tty: use time_is_before_jiffies() in n_tty_receive_overrun()
  tty: n_tty: use 'num' for writes' counts
  tty: n_tty: use output character directly
  tty: n_tty: make flow of n_tty_receive_buf_common() a bool
  Revert "tty: serial: meson: Add a earlycon for the T7 SoC"
  Documentation: devices.txt: Fix minors for ttyCPM*
  Documentation: devices.txt: Remove ttySIOC*
  Documentation: devices.txt: Remove ttyIOC*
  serial: 8250_bcm7271: improve bcm7271 8250 port
  ...
tty: ldops: unify to u8 2023-08-11T19:12:47+00:00 Jiri Slaby (SUSE) jirislaby@kernel.org 2023-08-10T09:15:05+00:00 49b8220cee4aa3d7aaaf42fd7f316b7f8fb710da Some hooks in struct tty_ldisc_ops still reference buffers by 'unsigned char'. Unify to 'u8' as the rest of the tty layer does. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Link: https://lore.kernel.org/r/20230810091510.13006-32-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Some hooks in struct tty_ldisc_ops still reference buffers by 'unsigned
char'. Unify to 'u8' as the rest of the tty layer does.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230810091510.13006-32-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: use u8 for flags 2023-08-11T19:12:45+00:00 Jiri Slaby (SUSE) jirislaby@kernel.org 2023-08-10T09:14:51+00:00 892bc209f250fb49ddca31c74d2c7b1126a7a61a This makes all those 'char's an explicit 'u8'. This is part of the continuing unification of chars and flags to be consistent u8. This approaches tty_port_default_receive_buf(). Note that we do not change signedness as we compile with -funsigned-char. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: William Hubbs <w.d.hubbs@gmail.com> Cc: Chris Brannon <chris@the-brannons.com> Cc: Kirk Reiser <kirk@reisers.ca> Cc: Samuel Thibault <samuel.thibault@ens-lyon.org> Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Max Staudt <max@enpas.org> Cc: Wolfgang Grandegger <wg@grandegger.com> Cc: Marc Kleine-Budde <mkl@pengutronix.de> Cc: Dario Binacchi <dario.binacchi@amarulasolutions.com> Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de> Cc: Jeremy Kerr <jk@codeconstruct.com.au> Cc: Matt Johnston <matt@codeconstruct.com.au> Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Cc: Liam Girdwood <lgirdwood@gmail.com> Cc: Mark Brown <broonie@kernel.org> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Takashi Iwai <tiwai@suse.com> Acked-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20230810091510.13006-18-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
This makes all those 'char's an explicit 'u8'. This is part of the
continuing unification of chars and flags to be consistent u8.

This approaches tty_port_default_receive_buf().

Note that we do not change signedness as we compile with
-funsigned-char.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: William Hubbs <w.d.hubbs@gmail.com>
Cc: Chris Brannon <chris@the-brannons.com>
Cc: Kirk Reiser <kirk@reisers.ca>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Max Staudt <max@enpas.org>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de>
Cc: Jeremy Kerr <jk@codeconstruct.com.au>
Cc: Matt Johnston <matt@codeconstruct.com.au>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Acked-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230810091510.13006-18-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>