From: Helge Deller <deller@gmx.de>
To: linux-parisc@vger.kernel.org
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>,
John David Anglin <dave.anglin@bell.net>
Subject: [PATCH 3/4] parisc: Check user signal stack trampoline is inside TASK_SIZE
Date: Wed, 8 Sep 2021 22:44:04 +0200 [thread overview]
Message-ID: <20210908204405.127665-3-deller@gmx.de> (raw)
In-Reply-To: <20210908204405.127665-1-deller@gmx.de>
Add some additional checks to ensure the signal stack is inside
userspace bounds.
Signed-off-by: Helge Deller <deller@gmx.de>
---
arch/parisc/kernel/signal.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)
diff --git a/arch/parisc/kernel/signal.c b/arch/parisc/kernel/signal.c
index 77db707ce391..46b1050640b8 100644
--- a/arch/parisc/kernel/signal.c
+++ b/arch/parisc/kernel/signal.c
@@ -237,18 +237,22 @@ setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs,
#endif
usp = (regs->gr[30] & ~(0x01UL));
+ sigframe_size = PARISC_RT_SIGFRAME_SIZE;
#ifdef CONFIG_64BIT
if (is_compat_task()) {
/* The gcc alloca implementation leaves garbage in the upper 32 bits of sp */
usp = (compat_uint_t)usp;
+ sigframe_size = PARISC_RT_SIGFRAME_SIZE32;
}
#endif
- /*FIXME: frame_size parameter is unused, remove it. */
- frame = get_sigframe(&ksig->ka, usp, sizeof(*frame));
+ frame = get_sigframe(&ksig->ka, usp, sigframe_size);
DBG(1,"SETUP_RT_FRAME: START\n");
DBG(1,"setup_rt_frame: frame %p info %p\n", frame, ksig->info);
+ start = (unsigned long) frame;
+ if (start >= user_addr_max() - sigframe_size)
+ return -EFAULT;
#ifdef CONFIG_64BIT
@@ -343,11 +347,6 @@ setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs,
/* The syscall return path will create IAOQ values from r31.
*/
- sigframe_size = PARISC_RT_SIGFRAME_SIZE;
-#ifdef CONFIG_64BIT
- if (is_compat_task())
- sigframe_size = PARISC_RT_SIGFRAME_SIZE32;
-#endif
if (in_syscall) {
regs->gr[31] = haddr;
#ifdef CONFIG_64BIT
@@ -518,6 +517,10 @@ insert_restart_trampoline(struct pt_regs *regs)
unsigned long end = (unsigned long) &usp[5];
long err = 0;
+ /* check that we don't exceed the stack */
+ if (A(&usp[0]) >= user_addr_max() - 5 * sizeof(int))
+ return;
+
/* Setup a trampoline to restart the syscall
* with __NR_restart_syscall
*
--
2.31.1
next prev parent reply other threads:[~2021-09-08 20:45 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-08 20:44 [PATCH 1/4] parisc: Drop strnlen_user() in favour of generic version Helge Deller
2021-09-08 20:44 ` [PATCH 2/4] parisc: Drop useless debug info and comments from signal.c Helge Deller
2021-09-08 20:44 ` Helge Deller [this message]
2021-09-08 20:44 ` [PATCH 4/4] parisc: Reduce sigreturn trampoline to 3 instructions Helge Deller
2021-11-15 22:25 ` John David Anglin
2021-11-16 13:54 ` Helge Deller
2021-11-16 15:31 ` John David Anglin
2021-11-16 17:08 ` John David Anglin
2021-11-16 19:02 ` Helge Deller
2021-11-16 19:12 ` John David Anglin
2021-09-08 21:26 ` [PATCH 1/4] parisc: Drop strnlen_user() in favour of generic version Arnd Bergmann
2021-09-08 21:40 ` Helge Deller
2021-09-08 22:08 ` Arnd Bergmann
2021-09-09 2:03 ` Helge Deller
2021-09-09 6:51 ` Arnd Bergmann
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