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authorLinus Torvalds <torvalds@linux-foundation.org>2008-10-09 14:04:54 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-10-09 14:26:38 -0700
commitefc968d450e013049a662d22727cf132618dcb2f (patch)
tree22b603182650a341922de5a640d5cceff1107cbc
parent07f405541892bd9bab4cca6c12499091ef4dd556 (diff)
downloadlinux-efc968d450e013049a662d22727cf132618dcb2f.tar.gz
Don't allow splice() to files opened with O_APPEND
This is debatable, but while we're debating it, let's disallow the combination of splice and an O_APPEND destination. It's not entirely clear what the semantics of O_APPEND should be, and POSIX apparently expects pwrite() to ignore O_APPEND, for example. So we could make up any semantics we want, including the old ones. But Miklos convinced me that we should at least give it some thought, and that accepting writes at arbitrary offsets is wrong at least for IS_APPEND() files (which always have O_APPEND set, even if the reverse isn't true: you can obviously have O_APPEND set on a regular file). So disallow O_APPEND entirely for now. I doubt anybody cares, and this way we have one less gray area to worry about. Reported-and-argued-for-by: Miklos Szeredi <miklos@szeredi.hu> Acked-by: Jens Axboe <ens.axboe@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/splice.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/splice.c b/fs/splice.c
index 1bbc6f4bb09..a1e701c2715 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -898,6 +898,9 @@ static long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
if (unlikely(!(out->f_mode & FMODE_WRITE)))
return -EBADF;
+ if (unlikely(out->f_flags & O_APPEND))
+ return -EINVAL;
+
ret = rw_verify_area(WRITE, out, ppos, len);
if (unlikely(ret < 0))
return ret;