From: Chuck Lever Date: Sat, 28 Dec 2024 17:55:17 +0000 (-0500) Subject: libfs: Return ENOSPC when the directory offset range is exhausted X-Git-Tag: v6.14-rc1~211^2^2~4 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=903dc9c43a155e0893280c7472d4a9a3a83d75a6;p=thirdparty%2Fkernel%2Flinux.git libfs: Return ENOSPC when the directory offset range is exhausted 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 Reviewed-by: Yang Erkun Signed-off-by: Chuck Lever Link: https://lore.kernel.org/r/20241228175522.1854234-2-cel@kernel.org Signed-off-by: Christian Brauner --- diff --git a/fs/libfs.c b/fs/libfs.c index 748ac59231547..3da58a92f48fe 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -292,8 +292,8 @@ int simple_offset_add(struct offset_ctx *octx, struct dentry *dentry) 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;