6.13-stable review patch. If anyone has any objections, please let me know.
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From: Chuck Lever chuck.lever@oracle.com
commit 903dc9c43a155e0893280c7472d4a9a3a83d75a6 upstream.
Testing shows that the EBUSY error return from mtree_alloc_cyclic() leaks into user space. The ERRORS section of "man creat(2)" says:
EBUSY O_EXCL was specified in flags and pathname refers to a block device that is in use by the system (e.g., it is mounted).
ENOSPC is closer to what applications expect in this situation.
Note that the normal range of simple directory offset values is 2..2^63, so hitting this error is going to be rare to impossible.
Fixes: 6faddda69f62 ("libfs: Add directory operations for stable offsets") Cc: stable@vger.kernel.org # v6.9+ Reviewed-by: Jeff Layton jlayton@kernel.org Reviewed-by: Yang Erkun yangerkun@huawei.com Signed-off-by: Chuck Lever chuck.lever@oracle.com Link: https://lore.kernel.org/r/20241228175522.1854234-2-cel@kernel.org Signed-off-by: Christian Brauner brauner@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/libfs.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/fs/libfs.c +++ b/fs/libfs.c @@ -292,8 +292,8 @@ int simple_offset_add(struct offset_ctx
ret = mtree_alloc_cyclic(&octx->mt, &offset, dentry, DIR_OFFSET_MIN, LONG_MAX, &octx->next_offset, GFP_KERNEL); - if (ret < 0) - return ret; + if (unlikely(ret < 0)) + return ret == -EBUSY ? -ENOSPC : ret;
offset_set(dentry, offset); return 0;