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| author | Thomas Garnier <thgarnie@google.com> | 2017-09-07 08:30:47 -0700 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2017-09-17 19:45:33 +0200 |
| commit | a2048e34d4655c06d31400646ae495bbfeb16b27 (patch) | |
| tree | c56a644d70480eb33d9015b8e47c95b0a46df9d0 /arch/arm64/kernel/signal.c | |
| parent | e33f8d32677fa4f4f8996ef46748f86aac81ccff (diff) | |
| download | lwn-a2048e34d4655c06d31400646ae495bbfeb16b27.tar.gz lwn-a2048e34d4655c06d31400646ae495bbfeb16b27.zip | |
arm64/syscalls: Move address limit check in loop
A bug was reported on ARM where set_fs might be called after it was
checked on the work pending function. ARM64 is not affected by this bug
but has a similar construct. In order to avoid any similar problems in
the future, the addr_limit_user_check function is moved at the beginning
of the loop.
Fixes: cf7de27ab351 ("arm64/syscalls: Check address limit on user-mode return")
Reported-by: Leonard Crestez <leonard.crestez@nxp.com>
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/1504798247-48833-5-git-send-email-keescook@chromium.org
Diffstat (limited to 'arch/arm64/kernel/signal.c')
| -rw-r--r-- | arch/arm64/kernel/signal.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index c45214f8fb54..0bdc96c61bc0 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -751,10 +751,10 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, */ trace_hardirqs_off(); - /* Check valid user FS if needed */ - addr_limit_user_check(); - do { + /* Check valid user FS if needed */ + addr_limit_user_check(); + if (thread_flags & _TIF_NEED_RESCHED) { schedule(); } else { |