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| author | Thomas Garnier <thgarnie@google.com> | 2017-09-07 08:30:44 -0700 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2017-09-17 19:45:32 +0200 |
| commit | bf29ed1567b67854dc13504f685c45a2ea9b2081 (patch) | |
| tree | 74bc82cb10d5af8b006ab4b9e06f3f1d6e8a12b8 | |
| parent | 0666f560b71b899cd11a7caf39fd45129e9030fd (diff) | |
| download | linux-bf29ed1567b67854dc13504f685c45a2ea9b2081.tar.gz linux-bf29ed1567b67854dc13504f685c45a2ea9b2081.tar.bz2 linux-bf29ed1567b67854dc13504f685c45a2ea9b2081.zip | |
syscalls: Use CHECK_DATA_CORRUPTION for addr_limit_user_check
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>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Pratyush Anand <panand@redhat.com>
Cc: Dave Martin <Dave.Martin@arm.com>
Cc: Will Drewry <wad@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: David Howells <dhowells@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-api@vger.kernel.org
Cc: Yonghong Song <yhs@fb.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1504798247-48833-2-git-send-email-keescook@chromium.org
| -rw-r--r-- | include/linux/syscalls.h | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 95606a2d556f..a78186d826d7 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -221,21 +221,25 @@ 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); |