From ca366fb107a76ee1c607d9b201cf450e705c3050 Mon Sep 17 00:00:00 2001
From: Pavel Begunkov <asml.silence@gmail.com>
Date: Fri, 31 Jan 2025 14:13:15 +0000
Subject: [PATCH] lib/iov_iter: fix import_iovec_ubuf iovec management
commit f4b78260fc678ccd7169f32dc9f3bfa3b93931c7 upstream.
import_iovec() says that it should always be fine to kfree the iovec
returned in @iovp regardless of the error code. __import_iovec_ubuf()
never reallocates it and thus should clear the pointer even in cases when
copy_iovec_*() fail.
Link: https://lkml.kernel.org/r/378ae26923ffc20fd5e41b4360d673bf47b1775b.1738332461.git.asml.silence@gmail.com
Fixes: 3b2deb0e46da ("iov_iter: import single vector iovecs as ITER_UBUF")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
lib/iov_iter.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 908e75a28d90b..bdb37d572e97c 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -1428,6 +1428,8 @@ static ssize_t __import_iovec_ubuf(int type, const struct iovec __user *uvec,
struct iovec *iov = *iovp;
ssize_t ret;
+ *iovp = NULL;
+
if (compat)
ret = copy_compat_iovec_from_user(iov, uvec, 1);
else
@@ -1438,7 +1440,6 @@ static ssize_t __import_iovec_ubuf(int type, const struct iovec __user *uvec,
ret = import_ubuf(type, iov->iov_base, iov->iov_len, i);
if (unlikely(ret))
return ret;
- *iovp = NULL;
return i->count;
}
--
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