From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Michael Ellerman <mpe@ellerman.id.au>
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: [PATCH 3/7] powerpc/signal64: Access function descriptor with user access block
Date: Tue, 15 Jun 2021 06:40:59 +0000 (UTC) [thread overview]
Message-ID: <9ce6e3e3bde4621442049476f41b5e0c7cf283be.1623739212.git.christophe.leroy@csgroup.eu> (raw)
In-Reply-To: <b813c1f4d3dab2f51300eac44d99029aa8e57830.1623739212.git.christophe.leroy@csgroup.eu>
Access the function descriptor of the handler within a
user access block.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/signal_64.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index 8b2eb758131c..9ca97b4366df 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -936,8 +936,18 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
func_descr_t __user *funct_desc_ptr =
(func_descr_t __user *) ksig->ka.sa.sa_handler;
- err |= get_user(regs->ctr, &funct_desc_ptr->entry);
- err |= get_user(regs->gpr[2], &funct_desc_ptr->toc);
+ if (user_read_access_begin(funct_desc_ptr, sizeof(func_descr_t))) {
+ unsafe_get_user(regs->ctr, &funct_desc_ptr->entry, bad_funct_desc_block);
+ unsafe_get_user(regs->gpr[2], &funct_desc_ptr->toc, bad_funct_desc_block);
+ } else {
+ goto bad_funct_desc;
+bad_funct_desc_block:
+ user_read_access_end();
+bad_funct_desc:
+ signal_fault(current, regs, __func__, funct_desc_ptr);
+ return 1;
+ }
+ user_read_access_end();
}
/* enter the signal handler in native-endian mode */
--
2.25.0
next prev parent reply other threads:[~2021-06-15 6:41 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-15 6:40 [PATCH 1/7] powerpc/signal64: Copy siginfo before changing regs->nip Christophe Leroy
2021-06-15 6:40 ` [PATCH 2/7] powerpc/signal64: Don't read sigaction arguments back from user memory Christophe Leroy
2021-06-15 6:40 ` Christophe Leroy [this message]
2021-06-15 6:41 ` [PATCH 4/7] powerpc/signal: Include the new stack frame inside the user access block Christophe Leroy
2021-06-15 6:41 ` [PATCH 5/7] signal: Add unsafe_copy_siginfo_to_user() Christophe Leroy
2021-06-15 6:52 ` Christoph Hellwig
2021-06-15 7:03 ` Christophe Leroy
2021-06-15 7:21 ` Christoph Hellwig
2021-06-15 7:28 ` Christophe Leroy
2021-06-15 6:41 ` [PATCH 6/7] powerpc/uaccess: Add unsafe_clear_user() Christophe Leroy
2021-06-15 6:53 ` Christoph Hellwig
2021-06-15 7:10 ` Christophe Leroy
2021-06-15 6:41 ` [PATCH 7/7] powerpc/signal: Use unsafe_copy_siginfo_to_user() Christophe Leroy
2021-06-15 6:55 ` Christoph Hellwig
2021-06-15 7:00 ` Christophe Leroy
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