Access the function descriptor of the handler within a
user access block.
Signed-off-by: Christophe Leroy <christophe.le...@csgroup.eu>
---
v3: Flatten the change to avoid nested gotos.
---
arch/powerpc/kernel/signal_64.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index 1831bba0582e..7b1cd50bc4fb 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -936,8 +936,13 @@ 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)))
+ goto badfunc;
+
+ unsafe_get_user(regs->ctr, &funct_desc_ptr->entry,
badfunc_block);
+ unsafe_get_user(regs->gpr[2], &funct_desc_ptr->toc,
badfunc_block);
+
+ user_read_access_end();
}
/* enter the signal handler in native-endian mode */
@@ -962,5 +967,12 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
badframe:
signal_fault(current, regs, "handle_rt_signal64", frame);
+ return 1;
+
+badfunc_block:
+ user_read_access_end();
+badfunc:
+ signal_fault(current, regs, __func__, (void __user
*)ksig->ka.sa.sa_handler);
+
return 1;
}
--
2.31.1
