Kuniyuki Iwashima e996507f59 atm: atmtcp: Free invalid length skb in atmtcp_c_send(). ... [ Upstream commit 2f370ae1fb ] syzbot reported the splat below. [0] vcc_sendmsg() copies data passed from userspace to skb and passes it to vcc->dev->ops->send(). atmtcp_c_send() accesses skb->data as struct atmtcp_hdr after checking if skb->len is 0, but it's not enough. Also, when skb->len == 0, skb and sk (vcc) were leaked because dev_kfree_skb() is not called and sk_wmem_alloc adjustment is missing to revert atm_account_tx() in vcc_sendmsg(), which is expected to be done in atm_pop_raw(). Let's properly free skb with an invalid length in atmtcp_c_send(). [0]: BUG: KMSAN: uninit-value in atmtcp_c_send+0x255/0xed0 drivers/atm/atmtcp.c:294 atmtcp_c_send+0x255/0xed0 drivers/atm/atmtcp.c:294 vcc_sendmsg+0xd7c/0xff0 net/atm/common.c:644 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x330/0x3d0 net/socket.c:727 ____sys_sendmsg+0x7e0/0xd80 net/socket.c:2566 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2620 __sys_sendmsg net/socket.c:2652 [inline] __do_sys_sendmsg net/socket.c:2657 [inline] __se_sys_sendmsg net/socket.c:2655 [inline] __x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2655 x64_sys_call+0x32fb/0x3db0 arch/x86/include/generated/asm/syscalls_64.h:47 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:4154 [inline] slab_alloc_node mm/slub.c:4197 [inline] kmem_cache_alloc_node_noprof+0x818/0xf00 mm/slub.c:4249 kmalloc_reserve+0x13c/0x4b0 net/core/skbuff.c:579 __alloc_skb+0x347/0x7d0 net/core/skbuff.c:670 alloc_skb include/linux/skbuff.h:1336 [inline] vcc_sendmsg+0xb40/0xff0 net/atm/common.c:628 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x330/0x3d0 net/socket.c:727 ____sys_sendmsg+0x7e0/0xd80 net/socket.c:2566 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2620 __sys_sendmsg net/socket.c:2652 [inline] __do_sys_sendmsg net/socket.c:2657 [inline] __se_sys_sendmsg net/socket.c:2655 [inline] __x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2655 x64_sys_call+0x32fb/0x3db0 arch/x86/include/generated/asm/syscalls_64.h:47 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: 5798 Comm: syz-executor192 Not tainted 6.16.0-rc1-syzkaller-00010-g2c4a1f3fe03e #0 PREEMPT(undef) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Fixes: 1da177e4c3 ("Linux-2.6.12-rc2") Reported-by: syzbot+1d3c235276f62963e93a@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=1d3c235276f62963e93a Tested-by: syzbot+1d3c235276f62963e93a@syzkaller.appspotmail.com Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250616182147.963333-2-kuni1840@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>		2025-06-27 11:11:43 +01:00
..
.gitignore
adummy.c
atmtcp.c	atm: atmtcp: Free invalid length skb in atmtcp_c_send().	2025-06-27 11:11:43 +01:00
eni.c	net: fill in MODULE_DESCRIPTION()s for ATM	2024-01-05 08:04:23 -08:00
eni.h
fore200e.c	atm/fore200e: Delete unused 'fore200e_boards'	2024-05-06 18:26:47 -07:00
fore200e.h	atm/fore200e: Delete unused 'fore200e_boards'	2024-05-06 18:26:47 -07:00
he.c
he.h
idt77105.c	net: fill in MODULE_DESCRIPTION()s for ATM	2024-01-05 08:04:23 -08:00
idt77105.h
idt77252_tables.h
idt77252.c	atm: idt77252: prevent use after free in dequeue_rx()	2024-08-12 10:41:44 +01:00
idt77252.h
iphase.c	net: fill in MODULE_DESCRIPTION()s for ATM	2024-01-05 08:04:23 -08:00
iphase.h
Kconfig
lanai.c
Makefile
midway.h
nicstar.c	net: fill in MODULE_DESCRIPTION()s for ATM	2024-01-05 08:04:23 -08:00
nicstar.h
nicstarmac.c
nicstarmac.copyright
solos-attrlist.c
solos-pci.c	atm: solos-pci: Fix potential deadlock on &tx_queue_lock	2023-12-09 21:17:45 +00:00
suni.c	net: fill in MODULE_DESCRIPTION()s for ATM	2024-01-05 08:04:23 -08:00
suni.h
tonga.h
zeprom.h