From: Kees Cook <keescook@chromium.org> To: Ingo Molnar <mingo@kernel.org> Cc: Kees Cook <keescook@chromium.org>, Thomas Garnier <thgarnie@google.com>, Thomas Gleixner <tglx@linutronix.de>, Russell King <linux@armlinux.org.uk>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will.deacon@arm.com>, Andy Lutomirski <luto@amacapital.net>, Will Drewry <wad@chromium.org>, Al Viro <viro@zeniv.linux.org.uk>, Dave Martin <Dave.Martin@arm.com>, Pratyush Anand <panand@redhat.com>, Dave Hansen <dave.hansen@intel.com>, Arnd Bergmann <arnd@arndb.de>, David Howells <dhowells@redhat.com>, Yonghong Song <yhs@fb.com>, linux-arm-kernel@lists.infradead.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/4] syscalls: Use CHECK_DATA_CORRUPTION for addr_limit_user_check Date: Thu, 7 Sep 2017 08:30:44 -0700 [thread overview] Message-ID: <1504798247-48833-2-git-send-email-keescook@chromium.org> (raw) In-Reply-To: <1504798247-48833-1-git-send-email-keescook@chromium.org> From: Thomas Garnier <thgarnie@google.com> Use CHECK_DATA_CORRUPTION instead of BUG_ON to provide more flexibility on address limit failures. By default, send a SIGKILL signal to kill the current process preventing exploitation of a bad address limit. Make the TIF_FSCHECK flag optional so ARM can use this function. Signed-off-by: Thomas Garnier <thgarnie@google.com> Signed-off-by: Kees Cook <keescook@chromium.org> --- include/linux/syscalls.h | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 88951b795ee3..65e273aadada 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -219,21 +219,25 @@ static inline int is_syscall_trace_event(struct trace_event_call *tp_event) } \ static inline long SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__)) -#ifdef TIF_FSCHECK /* * Called before coming back to user-mode. Returning to user-mode with an * address limit different than USER_DS can allow to overwrite kernel memory. */ static inline void addr_limit_user_check(void) { - +#ifdef TIF_FSCHECK if (!test_thread_flag(TIF_FSCHECK)) return; +#endif - BUG_ON(!segment_eq(get_fs(), USER_DS)); + if (CHECK_DATA_CORRUPTION(!segment_eq(get_fs(), USER_DS), + "Invalid address limit on user-mode return")) + force_sig(SIGKILL, current); + +#ifdef TIF_FSCHECK clear_thread_flag(TIF_FSCHECK); -} #endif +} asmlinkage long sys32_quotactl(unsigned int cmd, const char __user *special, qid_t id, void __user *addr); -- 2.7.4
WARNING: multiple messages have this Message-ID (diff)
From: keescook@chromium.org (Kees Cook) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 1/4] syscalls: Use CHECK_DATA_CORRUPTION for addr_limit_user_check Date: Thu, 7 Sep 2017 08:30:44 -0700 [thread overview] Message-ID: <1504798247-48833-2-git-send-email-keescook@chromium.org> (raw) In-Reply-To: <1504798247-48833-1-git-send-email-keescook@chromium.org> From: Thomas Garnier <thgarnie@google.com> Use CHECK_DATA_CORRUPTION instead of BUG_ON to provide more flexibility on address limit failures. By default, send a SIGKILL signal to kill the current process preventing exploitation of a bad address limit. Make the TIF_FSCHECK flag optional so ARM can use this function. Signed-off-by: Thomas Garnier <thgarnie@google.com> Signed-off-by: Kees Cook <keescook@chromium.org> --- include/linux/syscalls.h | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 88951b795ee3..65e273aadada 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -219,21 +219,25 @@ static inline int is_syscall_trace_event(struct trace_event_call *tp_event) } \ static inline long SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__)) -#ifdef TIF_FSCHECK /* * Called before coming back to user-mode. Returning to user-mode with an * address limit different than USER_DS can allow to overwrite kernel memory. */ static inline void addr_limit_user_check(void) { - +#ifdef TIF_FSCHECK if (!test_thread_flag(TIF_FSCHECK)) return; +#endif - BUG_ON(!segment_eq(get_fs(), USER_DS)); + if (CHECK_DATA_CORRUPTION(!segment_eq(get_fs(), USER_DS), + "Invalid address limit on user-mode return")) + force_sig(SIGKILL, current); + +#ifdef TIF_FSCHECK clear_thread_flag(TIF_FSCHECK); -} #endif +} asmlinkage long sys32_quotactl(unsigned int cmd, const char __user *special, qid_t id, void __user *addr); -- 2.7.4
next prev parent reply other threads:[~2017-09-07 15:31 UTC|newest] Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-09-07 15:30 [PATCH 0/4] Fix check address limit on user-mode Kees Cook 2017-09-07 15:30 ` Kees Cook 2017-09-07 15:30 ` Kees Cook [this message] 2017-09-07 15:30 ` [PATCH 1/4] syscalls: Use CHECK_DATA_CORRUPTION for addr_limit_user_check Kees Cook 2017-09-17 17:53 ` [tip:core/urgent] " tip-bot for Thomas Garnier 2017-09-07 15:30 ` [PATCH 2/4] Revert "arm/syscalls: Check address limit on user-mode return" Kees Cook 2017-09-07 15:30 ` Kees Cook 2017-09-17 17:54 ` [tip:core/urgent] " tip-bot for Thomas Garnier 2017-09-07 15:30 ` [PATCH 3/4] arm/syscalls: Optimize address limit check Kees Cook 2017-09-07 15:30 ` Kees Cook 2017-09-17 17:54 ` [tip:core/urgent] " tip-bot for Thomas Garnier 2017-09-07 15:30 ` [PATCH 4/4] arm64/syscalls: Move address limit check in loop Kees Cook 2017-09-07 15:30 ` Kees Cook 2017-09-12 18:27 ` Will Deacon 2017-09-12 18:27 ` Will Deacon 2017-09-12 18:28 ` Kees Cook 2017-09-12 18:28 ` Kees Cook 2017-09-12 18:28 ` Kees Cook 2017-09-13 8:00 ` Ingo Molnar 2017-09-13 8:00 ` Ingo Molnar 2017-09-13 8:00 ` Ingo Molnar 2017-09-17 17:54 ` [tip:core/urgent] " tip-bot for Thomas Garnier
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