This is a note to let you know that I've just added the patch titled
bpf: Add sockptr support for getsockopt
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
bpf-add-sockptr-support-for-getsockopt.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit b449aff2ab4abbc5713a20bfbeec63d8bcc39580
Author: Breno Leitao <leitao@xxxxxxxxxx>
Date: Mon Oct 16 06:47:39 2023 -0700
bpf: Add sockptr support for getsockopt
[ Upstream commit a615f67e1a426f35366b8398c11f31c148e7df48 ]
The whole network stack uses sockptr, and while it doesn't move to
something more modern, let's use sockptr in getsockptr BPF hooks, so, it
could be used by other callers.
The main motivation for this change is to use it in the io_uring
{g,s}etsockopt(), which will use a userspace pointer for *optval, but, a
kernel value for optlen.
Link: https://lore.kernel.org/all/ZSArfLaaGcfd8LH8@xxxxxxxxx/
Signed-off-by: Breno Leitao <leitao@xxxxxxxxxx>
Acked-by: Martin KaFai Lau <martin.lau@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20231016134750.1381153-2-leitao@xxxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Stable-dep-of: 33f339a1ba54 ("bpf, net: Fix a potential race in do_sock_getsockopt()")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h
index 31561e789715..c4956a48ab3e 100644
--- a/include/linux/bpf-cgroup.h
+++ b/include/linux/bpf-cgroup.h
@@ -140,9 +140,10 @@ int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
int __cgroup_bpf_run_filter_setsockopt(struct sock *sock, int *level,
int *optname, char __user *optval,
int *optlen, char **kernel_optval);
+
int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level,
- int optname, char __user *optval,
- int __user *optlen, int max_optlen,
+ int optname, sockptr_t optval,
+ sockptr_t optlen, int max_optlen,
int retval);
int __cgroup_bpf_run_filter_getsockopt_kern(struct sock *sk, int level,
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index ac37bd53aee0..caae07cc885e 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -1889,8 +1889,8 @@ int __cgroup_bpf_run_filter_setsockopt(struct sock *sk, int *level,
}
int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level,
- int optname, char __user *optval,
- int __user *optlen, int max_optlen,
+ int optname, sockptr_t optval,
+ sockptr_t optlen, int max_optlen,
int retval)
{
struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
@@ -1917,8 +1917,8 @@ int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level,
* one that kernel returned as well to let
* BPF programs inspect the value.
*/
-
- if (get_user(ctx.optlen, optlen)) {
+ if (copy_from_sockptr(&ctx.optlen, optlen,
+ sizeof(ctx.optlen))) {
ret = -EFAULT;
goto out;
}
@@ -1929,8 +1929,8 @@ int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level,
}
orig_optlen = ctx.optlen;
- if (copy_from_user(ctx.optval, optval,
- min(ctx.optlen, max_optlen)) != 0) {
+ if (copy_from_sockptr(ctx.optval, optval,
+ min(ctx.optlen, max_optlen))) {
ret = -EFAULT;
goto out;
}
@@ -1944,7 +1944,8 @@ int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level,
if (ret < 0)
goto out;
- if (optval && (ctx.optlen > max_optlen || ctx.optlen < 0)) {
+ if (!sockptr_is_null(optval) &&
+ (ctx.optlen > max_optlen || ctx.optlen < 0)) {
if (orig_optlen > PAGE_SIZE && ctx.optlen >= 0) {
pr_info_once("bpf getsockopt: ignoring program buffer with optlen=%d (max_optlen=%d)\n",
ctx.optlen, max_optlen);
@@ -1956,11 +1957,12 @@ int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level,
}
if (ctx.optlen != 0) {
- if (optval && copy_to_user(optval, ctx.optval, ctx.optlen)) {
+ if (!sockptr_is_null(optval) &&
+ copy_to_sockptr(optval, ctx.optval, ctx.optlen)) {
ret = -EFAULT;
goto out;
}
- if (put_user(ctx.optlen, optlen)) {
+ if (copy_to_sockptr(optlen, &ctx.optlen, sizeof(ctx.optlen))) {
ret = -EFAULT;
goto out;
}
diff --git a/net/socket.c b/net/socket.c
index 8d83c4bb163b..b2d75d5661be 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2375,8 +2375,9 @@ int __sys_getsockopt(int fd, int level, int optname, char __user *optval,
if (!in_compat_syscall())
err = BPF_CGROUP_RUN_PROG_GETSOCKOPT(sock->sk, level, optname,
- optval, optlen, max_optlen,
- err);
+ USER_SOCKPTR(optval),
+ USER_SOCKPTR(optlen),
+ max_optlen, err);
out_put:
fput_light(sock->file, fput_needed);
return err;
