2020-11-20 17:08:14

by Jann Horn

Subject: [PATCH v2] seccomp: Remove bogus __user annotations

Buffers that are passed to read_actions_logged() and write_actions_logged()
are in kernel memory; the sysctl core takes care of copying from/to
userspace.

Fixes: 32927393dc1c ("sysctl: pass kernel pointers to ->proc_handler")
Reviewed-by: Tyler Hicks <[email protected]>
Signed-off-by: Jann Horn <[email protected]>
---
v2: corrected "Fixes" tag

kernel/seccomp.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index 8ad7a293255a..c2bff3561846 100644
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -1968,7 +1968,7 @@ static bool seccomp_actions_logged_from_names(u32 *actions_logged, char *names)
return true;
}

-static int read_actions_logged(struct ctl_table *ro_table, void __user *buffer,
+static int read_actions_logged(struct ctl_table *ro_table, void *buffer,
size_t *lenp, loff_t *ppos)
{
char names[sizeof(seccomp_actions_avail)];
@@ -1986,7 +1986,7 @@ static int read_actions_logged(struct ctl_table *ro_table, void __user *buffer,
return proc_dostring(&table, 0, buffer, lenp, ppos);
}

-static int write_actions_logged(struct ctl_table *ro_table, void __user *buffer,
+static int write_actions_logged(struct ctl_table *ro_table, void *buffer,
size_t *lenp, loff_t *ppos, u32 *actions_logged)
{
char names[sizeof(seccomp_actions_avail)];

base-commit: 4d02da974ea85a62074efedf354e82778f910d82
--
2.29.2.454.gaff20da3a2-goog

2020-11-20 19:44:50

by Kees Cook

Subject: Re: [PATCH v2] seccomp: Remove bogus __user annotations

On Fri, 20 Nov 2020 18:05:45 +0100, Jann Horn wrote:
> Buffers that are passed to read_actions_logged() and write_actions_logged()
> are in kernel memory; the sysctl core takes care of copying from/to
> userspace.

Applied to for-next/seccomp, thanks!

[1/1] seccomp: Remove bogus __user annotations
https://git.kernel.org/kees/c/fab686eb0307

--
Kees Cook