From 41cd780524674082b037e7c8461f90c5e42103f0 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Fri, 3 Apr 2020 07:20:51 +0000 Subject: uaccess: Selectively open read or write user access When opening user access to only perform reads, only open read access. When opening user access to only perform writes, only open write access. Signed-off-by: Christophe Leroy Reviewed-by: Kees Cook Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/2e73bc57125c2c6ab12a587586a4eed3a47105fc.1585898438.git.christophe.leroy@c-s.fr --- kernel/exit.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'kernel/exit.c') diff --git a/kernel/exit.c b/kernel/exit.c index 389a88cb3081..2d97cbba512d 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -1557,7 +1557,7 @@ SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *, if (!infop) return err; - if (!user_access_begin(infop, sizeof(*infop))) + if (!user_write_access_begin(infop, sizeof(*infop))) return -EFAULT; unsafe_put_user(signo, &infop->si_signo, Efault); @@ -1566,10 +1566,10 @@ SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *, unsafe_put_user(info.pid, &infop->si_pid, Efault); unsafe_put_user(info.uid, &infop->si_uid, Efault); unsafe_put_user(info.status, &infop->si_status, Efault); - user_access_end(); + user_write_access_end(); return err; Efault: - user_access_end(); + user_write_access_end(); return -EFAULT; } @@ -1684,7 +1684,7 @@ COMPAT_SYSCALL_DEFINE5(waitid, if (!infop) return err; - if (!user_access_begin(infop, sizeof(*infop))) + if (!user_write_access_begin(infop, sizeof(*infop))) return -EFAULT; unsafe_put_user(signo, &infop->si_signo, Efault); @@ -1693,10 +1693,10 @@ COMPAT_SYSCALL_DEFINE5(waitid, unsafe_put_user(info.pid, &infop->si_pid, Efault); unsafe_put_user(info.uid, &infop->si_uid, Efault); unsafe_put_user(info.status, &infop->si_status, Efault); - user_access_end(); + user_write_access_end(); return err; Efault: - user_access_end(); + user_write_access_end(); return -EFAULT; } #endif -- cgit v1.2.3