[PATCH 3/7] powerpc/signal64: Access function descriptor with user access block
From: Christophe Leroy <hidden>
Date: 2021-06-15 06:41:31
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
Access the function descriptor of the handler within a user access block. Signed-off-by: Christophe Leroy <redacted> --- 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