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| author | Andrey Ryabinin <aryabinin@virtuozzo.com> | 2018-07-17 19:00:33 +0300 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2018-12-17 01:08:26 +0300 |
| commit | 2d74743c19298b69268e4a62c0e439d75c3010e4 (patch) | |
| tree | 097f901f7568c542df6946110d6d4b9786c53c86 | |
| parent | 84dd9744f4adb87b5a830b3097047a3f0099ccf5 (diff) | |
| download | linux-2d74743c19298b69268e4a62c0e439d75c3010e4.tar.xz | |
fuse: Don't access pipe->buffers without pipe_lock()
commit a2477b0e67c52f4364a47c3ad70902bc2a61bd4c upstream.
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>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -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 f2bbb8513360..0834f5640875 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -1913,11 +1913,14 @@ static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe, if (!fc) return -EPERM; + pipe_lock(pipe); + bufs = kmalloc(pipe->buffers * sizeof(struct pipe_buffer), GFP_KERNEL); - if (!bufs) + if (!bufs) { + pipe_unlock(pipe); return -ENOMEM; + } - pipe_lock(pipe); nbuf = 0; rem = 0; for (idx = 0; idx < pipe->nrbufs && rem < len; idx++) |