diff options
author | Andrey Ryabinin <aryabinin@virtuozzo.com> | 2018-07-17 12:00:33 -0400 |
---|---|---|
committer | Miklos Szeredi <mszeredi@redhat.com> | 2018-07-26 10:13:11 -0400 |
commit | a2477b0e67c52f4364a47c3ad70902bc2a61bd4c (patch) | |
tree | cb4724a138dccddd5f972b3174d075bf02cf2914 | |
parent | 63576c13bd17848376c8ba4a98f5d5151140c4ac (diff) |
fuse: Don't access pipe->buffers without pipe_lock()
fuse_dev_splice_write() reads pipe->buffers to determine the size of
'bufs' array before taking the pipe_lock(). This is not safe as
another thread might change the 'pipe->buffers' between the allocation
and taking the pipe_lock(). So we end up with too small 'bufs' array.
Move the bufs allocations inside pipe_lock()/pipe_unlock() to fix this.
Fixes: dd3bb14f44a6 ("fuse: support splice() writing to fuse device")
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: <stable@vger.kernel.org> # v2.6.35
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
-rw-r--r-- | fs/fuse/dev.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index ec83b107c1a0..4a9ace7280b9 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c | |||
@@ -1955,12 +1955,15 @@ static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe, | |||
1955 | if (!fud) | 1955 | if (!fud) |
1956 | return -EPERM; | 1956 | return -EPERM; |
1957 | 1957 | ||
1958 | pipe_lock(pipe); | ||
1959 | |||
1958 | bufs = kmalloc_array(pipe->buffers, sizeof(struct pipe_buffer), | 1960 | bufs = kmalloc_array(pipe->buffers, sizeof(struct pipe_buffer), |
1959 | GFP_KERNEL); | 1961 | GFP_KERNEL); |
1960 | if (!bufs) | 1962 | if (!bufs) { |
1963 | pipe_unlock(pipe); | ||
1961 | return -ENOMEM; | 1964 | return -ENOMEM; |
1965 | } | ||
1962 | 1966 | ||
1963 | pipe_lock(pipe); | ||
1964 | nbuf = 0; | 1967 | nbuf = 0; |
1965 | rem = 0; | 1968 | rem = 0; |
1966 | for (idx = 0; idx < pipe->nrbufs && rem < len; idx++) | 1969 | for (idx = 0; idx < pipe->nrbufs && rem < len; idx++) |