4.19-stable review patch. If anyone has any objections, please let me know.
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From: Filipe Manana fdmanana@suse.com
[ Upstream commit dec96fc2dcb59723e041416b8dc53e011b4bfc2e ]
In the tree search v2 ioctl we use the type size_t, which is an unsigned long, to track the buffer size in the local variable 'buf_size'. An unsigned long is 32 bits wide on a 32 bits architecture. The buffer size defined in struct btrfs_ioctl_search_args_v2 is a u64, so when we later try to copy the local variable 'buf_size' to the argument struct, when the search returns -EOVERFLOW, we copy only 32 bits which will be a problem on big endian systems.
Fix this by using a u64 type for the buffer sizes, not only at btrfs_ioctl_tree_search_v2(), but also everywhere down the call chain so that we can use the u64 at btrfs_ioctl_tree_search_v2().
Fixes: cc68a8a5a433 ("btrfs: new ioctl TREE_SEARCH_V2") Reported-by: Dan Carpenter dan.carpenter@linaro.org Link: https://lore.kernel.org/linux-btrfs/ce6f4bd6-9453-4ffe-ba00-cee35495e10f@mor... Signed-off-by: Filipe Manana fdmanana@suse.com Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/btrfs/ioctl.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index e3f18edc1afee..23beabb489231 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -2045,7 +2045,7 @@ static noinline int key_in_sk(struct btrfs_key *key, static noinline int copy_to_sk(struct btrfs_path *path, struct btrfs_key *key, struct btrfs_ioctl_search_key *sk, - size_t *buf_size, + u64 *buf_size, char __user *ubuf, unsigned long *sk_offset, int *num_found) @@ -2177,7 +2177,7 @@ static noinline int copy_to_sk(struct btrfs_path *path,
static noinline int search_ioctl(struct inode *inode, struct btrfs_ioctl_search_key *sk, - size_t *buf_size, + u64 *buf_size, char __user *ubuf) { struct btrfs_fs_info *info = btrfs_sb(inode->i_sb); @@ -2249,7 +2249,7 @@ static noinline int btrfs_ioctl_tree_search(struct file *file, struct btrfs_ioctl_search_key sk; struct inode *inode; int ret; - size_t buf_size; + u64 buf_size;
if (!capable(CAP_SYS_ADMIN)) return -EPERM; @@ -2283,8 +2283,8 @@ static noinline int btrfs_ioctl_tree_search_v2(struct file *file, struct btrfs_ioctl_search_args_v2 args; struct inode *inode; int ret; - size_t buf_size; - const size_t buf_limit = SZ_16M; + u64 buf_size; + const u64 buf_limit = SZ_16M;
if (!capable(CAP_SYS_ADMIN)) return -EPERM;