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author | Al Viro <viro@zeniv.linux.org.uk> | 2021-03-25 14:12:34 -0400 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-04-14 08:42:06 +0200 |
commit | e5a3449ce16a24bc53c9f41cf36418abe6c27a72 (patch) | |
tree | 7a2292ce83b892d81547799d265739ba285ad630 | |
parent | 3cc4db1213a44aa5d7838dfb22ce78281da1f7cc (diff) | |
download | linux-stable-e5a3449ce16a24bc53c9f41cf36418abe6c27a72.tar.gz linux-stable-e5a3449ce16a24bc53c9f41cf36418abe6c27a72.tar.bz2 linux-stable-e5a3449ce16a24bc53c9f41cf36418abe6c27a72.zip |
hostfs: fix memory handling in follow_link()
[ Upstream commit 7f6c411c9b50cfab41cc798e003eff27608c7016 ]
1) argument should not be freed in any case - the caller already has
it as ->s_fs_info (and uses it a lot afterwards)
2) allocate readlink buffer with kmalloc() - the caller has no way
to tell if it's got that (on absolute symlink) or a result of
kasprintf(). Sure, for SLAB and SLUB kfree() works on results of
kmem_cache_alloc(), but that's not documented anywhere, might change
in the future *and* is already not true for SLOB.
Fixes: 52b209f7b848 ("get rid of hostfs_read_inode()")
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r-- | fs/hostfs/hostfs_kern.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c index c070c0d8e3e9..d4e360234579 100644 --- a/fs/hostfs/hostfs_kern.c +++ b/fs/hostfs/hostfs_kern.c @@ -142,7 +142,7 @@ static char *follow_link(char *link) char *name, *resolved, *end; int n; - name = __getname(); + name = kmalloc(PATH_MAX, GFP_KERNEL); if (!name) { n = -ENOMEM; goto out_free; @@ -171,12 +171,11 @@ static char *follow_link(char *link) goto out_free; } - __putname(name); - kfree(link); + kfree(name); return resolved; out_free: - __putname(name); + kfree(name); return ERR_PTR(n); } |