From: Andy Lutomirski <luto@kernel.org>
To: x86@kernel.org
Cc: LKML <linux-kernel@vger.kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Andy Lutomirski <luto@kernel.org>,
stable@vger.kernel.org
Subject: [PATCH v3 01/11] x86/entry: Fix entry/exit mismatch on failed fast 32-bit syscalls
Date: Thu, 4 Mar 2021 11:05:54 -0800 [thread overview]
Message-ID: <8c82296ddf803b91f8d1e5eac89e5803ba54ab0e.1614884673.git.luto@kernel.org> (raw)
In-Reply-To: <cover.1614884673.git.luto@kernel.org>
On a 32-bit fast syscall that fails to read its arguments from user
memory, the kernel currently does syscall exit work but not
syscall entry work. This confuses audit and ptrace. For example:
$ ./tools/testing/selftests/x86/syscall_arg_fault_32
...
strace: pid 264258: entering, ptrace_syscall_info.op == 2
...
This is a minimal fix intended for ease of backporting. A more
complete cleanup is coming.
Cc: stable@vger.kernel.org
Fixes: 0b085e68f407 ("x86/entry: Consolidate 32/64 bit syscall entry")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
arch/x86/entry/common.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index 0904f5676e4d..8fdb4cb27efe 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -128,7 +128,8 @@ static noinstr bool __do_fast_syscall_32(struct pt_regs *regs)
regs->ax = -EFAULT;
instrumentation_end();
- syscall_exit_to_user_mode(regs);
+ local_irq_disable();
+ irqentry_exit_to_user_mode(regs);
return false;
}
--
2.29.2
next prev parent reply other threads:[~2021-03-04 19:07 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-04 19:05 [PATCH v3 00/11] kentry: A stable bugfix and a bunch of improvements Andy Lutomirski
2021-03-04 19:05 ` Andy Lutomirski [this message]
2021-03-05 10:16 ` [tip: x86/urgent] x86/entry: Fix entry/exit mismatch on failed fast 32-bit syscalls tip-bot2 for Andy Lutomirski
2021-03-06 10:44 ` tip-bot2 for Andy Lutomirski
2021-03-06 12:18 ` tip-bot2 for Andy Lutomirski
2021-03-04 19:05 ` [PATCH v3 02/11] kentry: Rename irqentry to kentry Andy Lutomirski
2021-03-08 9:45 ` Mark Rutland
2021-03-04 19:05 ` [PATCH v3 03/11] x86/dumpstack: Remove unnecessary range check fetching opcode bytes Andy Lutomirski
2021-03-04 19:05 ` [PATCH v3 04/11] x86/kthread,dumpstack: Set task_pt_regs->cs.RPL=3 for kernel threads Andy Lutomirski
2021-03-04 20:19 ` Ira Weiny
2021-03-04 19:05 ` [PATCH v3 05/11] x86/entry: Convert ret_from_fork to C Andy Lutomirski
2021-03-05 0:55 ` Brian Gerst
2021-03-04 19:05 ` [PATCH v3 06/11] kentry: Simplify the common syscall API Andy Lutomirski
2021-03-08 9:49 ` Mark Rutland
2021-03-04 19:06 ` [PATCH v3 07/11] kentry: Make entry/exit_to_user_mode() arm64-only Andy Lutomirski
2021-03-08 10:06 ` Mark Rutland
2021-03-14 1:18 ` Andy Lutomirski
2021-03-04 19:06 ` [PATCH v3 08/11] entry: Make CONFIG_DEBUG_ENTRY available outside x86 Andy Lutomirski
2021-03-08 10:13 ` Mark Rutland
2021-03-29 11:50 ` Sven Schnelle
2021-03-04 19:06 ` [PATCH v3 09/11] kentry: Add debugging checks for proper kentry API usage Andy Lutomirski
2021-03-04 19:06 ` [PATCH v3 10/11] kentry: Check that syscall entries and syscall exits match Andy Lutomirski
2021-03-04 19:06 ` [PATCH v3 11/11] kentry: Verify kentry state in instrumentation_begin/end() Andy Lutomirski
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