From 4310c6b8e75d6a47f7548e5948fbe6318aa4440a Mon Sep 17 00:00:00 2001 From: Fedor Pchelkin Date: Mon, 31 Aug 2026 10:58:09 +0300 Subject: thunderbolt: Fix NULL dereference in tb_remove_work() There is a slight race between tb_remove_work() and tb_domain_remove() which leads to dereferencing a NULL tb->root_switch pointer inside tb_free_unplugged_xdomains(): Thread A Thread B tb_remove_work() tb_domain_remove() mutex_lock(&tb->lock) tb_stop() /* doesn't cancel a running callback */ cancel_delayed_work(&tcm->remove_work) ... tb_switch_remove(tb->root_switch) tb->root_switch = NULL mutex_unlock(&tb->lock) mutex_lock(&tb->lock) ... /* without checking ->root_switch */ tb_free_unplugged_xdomains(tb->root_switch) mutex_unlock(&tb->lock) Commit a8937f35cf39 ("thunderbolt: Remove XDomain from the bus without holding tb->lock") doesn't seem right to move tb_free_unplugged_xdomains() out of the &tb->lock section and the check for tb->root_switch, in particular. It states: For this reason separate removing the XDomain from the topology data structures (where we need the lock) from unregistering the device from the bus (where remove callbacks of the drivers are being called). tb_free_unplugged_xdomains() belongs to the former group of functions requiring the lock. And it also calls tb_xdomain_remove() which should only be called with &tb->lock held. Found by Linux Verification Center (linuxtesting.org) with Svace static analysis tool. Fixes: a8937f35cf39 ("thunderbolt: Remove XDomain from the bus without holding tb->lock") Cc: stable@vger.kernel.org Signed-off-by: Fedor Pchelkin Signed-off-by: Mika Westerberg --- include/asm-generic/seccomp.h | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100644 include/asm-generic/seccomp.h (limited to 'include/asm-generic/seccomp.h') diff --git a/include/asm-generic/seccomp.h b/include/asm-generic/seccomp.h new file mode 100644 index 000000000..6b6f42bc5 --- /dev/null +++ b/include/asm-generic/seccomp.h @@ -0,0 +1,43 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * include/asm-generic/seccomp.h + * + * Copyright (C) 2014 Linaro Limited + * Author: AKASHI Takahiro + */ +#ifndef _ASM_GENERIC_SECCOMP_H +#define _ASM_GENERIC_SECCOMP_H + +#include + +#if defined(CONFIG_COMPAT) && !defined(__NR_seccomp_read_32) +#define __NR_seccomp_read_32 __NR_read +#define __NR_seccomp_write_32 __NR_write +#define __NR_seccomp_exit_32 __NR_exit +#ifndef __NR_seccomp_sigreturn_32 +#define __NR_seccomp_sigreturn_32 __NR_rt_sigreturn +#endif +#endif /* CONFIG_COMPAT && ! already defined */ + +#define __NR_seccomp_read __NR_read +#define __NR_seccomp_write __NR_write +#define __NR_seccomp_exit __NR_exit +#ifndef __NR_seccomp_sigreturn +#define __NR_seccomp_sigreturn __NR_rt_sigreturn +#endif + +#ifdef CONFIG_COMPAT +#ifndef get_compat_mode1_syscalls +static inline const int *get_compat_mode1_syscalls(void) +{ + static const int mode1_syscalls_32[] = { + __NR_seccomp_read_32, __NR_seccomp_write_32, + __NR_seccomp_exit_32, __NR_seccomp_sigreturn_32, + -1, /* negative terminated */ + }; + return mode1_syscalls_32; +} +#endif +#endif /* CONFIG_COMPAT */ + +#endif /* _ASM_GENERIC_SECCOMP_H */ -- cgit v1.3.1