kernel/linux.git/drivers/net/slip, branch v6.1.175

slip: bound decode() reads against the compressed packet length

2026-06-01T15:39:25+00:00

[ Upstream commit 4c1367a2d7aad643a6f87c6931b13cc1a25e8ca7 ] slhc_uncompress() parses a VJ-compressed TCP header by advancing a pointer through the packet via decode() and pull16(). Neither helper bounds-checks against isize, and decode() masks its return with & 0xffff so it can never return the -1 that callers test for -- those error paths are dead code. A short compressed frame whose change byte requests optional fields lets decode() read past the end of the packet. The over-read bytes are folded into the cached cstate and reflected into subsequent reconstructed packets. Make decode() and pull16() take the packet end pointer and return -1 when exhausted. Add a bounds check before the TCP-checksum read. The existing == -1 tests now do what they were always meant to. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Simon Horman Closes: https://lore.kernel.org/netdev/20260414134126.758795-2-horms@kernel.org/ Signed-off-by: Weiming Shi Reviewed-by: Simon Horman Link: https://patch.msgid.link/20260416100147.531855-5-bestswngs@gmail.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

slip: reject VJ receive packets on instances with no rstate array

2026-06-01T15:39:25+00:00

[ Upstream commit e76607442d5b73e1ba6768f501ef815bb58c2c0e ] slhc_init() accepts rslots == 0 as a valid configuration, with the documented meaning of 'no receive compression'. In that case the allocation loop in slhc_init() is skipped, so comp->rstate stays NULL and comp->rslot_limit stays 0 (from the kzalloc of struct slcompress). The receive helpers do not defend against that configuration. slhc_uncompress() dereferences comp->rstate[x] when the VJ header carries an explicit connection ID, and slhc_remember() later assigns cs = &comp->rstate[...] after only comparing the packet's slot number to comp->rslot_limit. Because rslot_limit is 0, slot 0 passes the range check, and the code dereferences a NULL rstate. The configuration is reachable in-tree through PPP. PPPIOCSMAXCID stores its argument in a signed int, and (val >> 16) uses arithmetic shift. Passing 0xffff0000 therefore sign-extends to -1, so val2 + 1 is 0 and ppp_generic.c ends up calling slhc_init(0, 1). Because /dev/ppp open is gated by ns_capable(CAP_NET_ADMIN), the whole path is reachable from an unprivileged user namespace. Once the malformed VJ state is installed, any inbound VJ-compressed or VJ-uncompressed frame that selects slot 0 crashes the kernel in softirq context: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] RIP: 0010:slhc_uncompress (drivers/net/slip/slhc.c:519) Call Trace: ppp_receive_nonmp_frame (drivers/net/ppp/ppp_generic.c:2466) ppp_input (drivers/net/ppp/ppp_generic.c:2359) ppp_async_process (drivers/net/ppp/ppp_async.c:492) tasklet_action_common (kernel/softirq.c:926) handle_softirqs (kernel/softirq.c:623) run_ksoftirqd (kernel/softirq.c:1055) smpboot_thread_fn (kernel/smpboot.c:160) kthread (kernel/kthread.c:436) ret_from_fork (arch/x86/kernel/process.c:164) Reject the receive side on such instances instead of touching rstate. slhc_uncompress() falls through to its existing 'bad' label, which bumps sls_i_error and enters the toss state. slhc_remember() mirrors that with an explicit sls_i_error increment followed by slhc_toss(); the sls_i_runt counter is not used here because a missing rstate is an internal configuration state, not a runt packet. The transmit path is unaffected: the only in-tree caller that picks rslots from userspace (ppp_generic.c) still supplies tslots >= 1, and slip.c always calls slhc_init(16, 16), so comp->tstate remains valid and slhc_compress() continues to work. Fixes: 4ab42d78e37a ("ppp, slip: Validate VJ compression slot parameters completely") Reported-by: Xiang Mei Signed-off-by: Weiming Shi Reviewed-by: Simon Horman Link: https://patch.msgid.link/20260415204130.258866-2-bestswngs@gmail.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

slip: make slhc_remember() more robust against malicious packets

2024-10-17T13:22:23+00:00

[ Upstream commit 7d3fce8cbe3a70a1c7c06c9b53696be5d5d8dd5c ] syzbot found that slhc_remember() was missing checks against malicious packets [1]. slhc_remember() only checked the size of the packet was at least 20, which is not good enough. We need to make sure the packet includes the IPv4 and TCP header that are supposed to be carried. Add iph and th pointers to make the code more readable. [1] BUG: KMSAN: uninit-value in slhc_remember+0x2e8/0x7b0 drivers/net/slip/slhc.c:666 slhc_remember+0x2e8/0x7b0 drivers/net/slip/slhc.c:666 ppp_receive_nonmp_frame+0xe45/0x35e0 drivers/net/ppp/ppp_generic.c:2455 ppp_receive_frame drivers/net/ppp/ppp_generic.c:2372 [inline] ppp_do_recv+0x65f/0x40d0 drivers/net/ppp/ppp_generic.c:2212 ppp_input+0x7dc/0xe60 drivers/net/ppp/ppp_generic.c:2327 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: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: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: 0 UID: 0 PID: 5460 Comm: syz.2.33 Not tainted 6.12.0-rc2-syzkaller-00006-g87d6aab2389e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Fixes: b5451d783ade ("slip: Move the SLIP drivers") Reported-by: syzbot+2ada1bc857496353be5a@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/670646db.050a0220.3f80e.0027.GAE@google.com/T/#u Signed-off-by: Eric Dumazet Link: https://patch.msgid.link/20241009091132.2136321-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

drivers: net: slip: fix NPD bug in sl_tx_timeout()

2022-04-07T06:00:16+00:00

When a slip driver is detaching, the slip_close() will act to cleanup necessary resources and sl->tty is set to NULL in slip_close(). Meanwhile, the packet we transmit is blocked, sl_tx_timeout() will be called. Although slip_close() and sl_tx_timeout() use sl->lock to synchronize, we don`t judge whether sl->tty equals to NULL in sl_tx_timeout() and the null pointer dereference bug will happen. (Thread 1) | (Thread 2) | slip_close() | spin_lock_bh(&sl->lock) | ... ... | sl->tty = NULL //(1) sl_tx_timeout() | spin_unlock_bh(&sl->lock) spin_lock(&sl->lock); | ... | ... tty_chars_in_buffer(sl->tty)| if (tty->ops->..) //(2) | ... | synchronize_rcu() We set NULL to sl->tty in position (1) and dereference sl->tty in position (2). This patch adds check in sl_tx_timeout(). If sl->tty equals to NULL, sl_tx_timeout() will goto out. Signed-off-by: Duoming Zhou Reviewed-by: Jiri Slaby Link: https://lore.kernel.org/r/20220405132206.55291-1-duoming@zju.edu.cn Signed-off-by: Jakub Kicinski

slip/plip: Use netif_rx().

2022-03-06T11:05:31+00:00

Since commit baebdf48c3600 ("net: dev: Makes sure netif_rx() can be invoked in any context.") the function netif_rx() can be used in preemptible/thread context as well as in interrupt context. Use netif_rx(). Signed-off-by: Sebastian Andrzej Siewior Acked-by: Oliver Hartkopp Signed-off-by: David S. Miller

Merge 5.16-rc4 into tty-next

2021-12-06T08:32:47+00:00

We need the tty/serial driver fixes in here as well. Signed-off-by: Greg Kroah-Hartman

tty: remove file from tty_ldisc_ops::ioctl and compat_ioctl

2021-11-25T17:36:27+00:00

After the previous patches, noone needs 'file' parameter in neither ioctl hook from tty_ldisc_ops. So remove 'file' from both of them. Cc: Marcel Holtmann Cc: Johan Hedberg Cc: Luiz Augusto von Dentz Cc: Wolfgang Grandegger Cc: Marc Kleine-Budde Cc: "David S. Miller" Cc: Jakub Kicinski Cc: Andreas Koensgen Cc: Paul Mackerras Acked-by: Krzysztof Kozlowski [NFC] Acked-by: Dmitry Torokhov Acked-by: Marc Kleine-Budde Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20211122094529.24171-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman

slip: fix macro redefine warning

2021-11-23T11:38:13+00:00

MIPS/IA64 define END as assembly function ending, which conflict with END definition in slip.h, just undef it at first Reported-by: lkp@intel.com Signed-off-by: Huang Pei Signed-off-by: David S. Miller

tty: remove file from tty_mode_ioctl

2021-09-22T14:59:13+00:00

The only user of 'file' parameter in tty_mode_ioctl is a BUG_ON check. Provided it never crashed for anyone, it's an overkill to pass the parameter to tty_mode_ioctl only for this check. If we wanted to check 'file' there, we should handle it in more graceful way anyway. Not by a BUG == crash. Cc: Wolfgang Grandegger Cc: Marc Kleine-Budde Cc: "David S. Miller" Cc: Jakub Kicinski Cc: Andreas Koensgen Cc: Paul Mackerras Acked-by: Marc Kleine-Budde Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20210914091134.17426-5-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman

tty: make tty_ldisc_ops::hangup return void

2021-09-22T14:59:13+00:00

The documentation says that the return value of tty_ldisc_ops::hangup hook is ignored. And it really is, so there is no point for its return type to be int. Switch it to void and all the hooks too. Cc: Dmitry Torokhov Cc: Wolfgang Grandegger Cc: Marc Kleine-Budde Cc: "David S. Miller" Cc: Jakub Kicinski Cc: Paul Mackerras Cc: Liam Girdwood Cc: Mark Brown Cc: Jaroslav Kysela Cc: Takashi Iwai Cc: Peter Ujfalusi Acked-by: Dmitry Torokhov Acked-by: Mark Brown Acked-by: Marc Kleine-Budde Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20210914091134.17426-4-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman