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| author | Sven Wegener <sven.wegener@stealer.net> | 2012-12-08 15:30:18 +0100 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2012-12-11 09:14:50 -0500 |
| commit | 7d3e91a89b7adbc2831334def9e494dd9892f9af (patch) | |
| tree | 7069dabbdabe013f21b56ea1641875ef4d5bb283 /fs/nfs/nfs4proc.c | |
| parent | 4c1002100898d03c5c9142ffaf58351c841ab94a (diff) | |
| download | lwn-7d3e91a89b7adbc2831334def9e494dd9892f9af.tar.gz lwn-7d3e91a89b7adbc2831334def9e494dd9892f9af.zip | |
NFSv4: Check for buffer length in __nfs4_get_acl_uncached
Commit 1f1ea6c "NFSv4: Fix buffer overflow checking in
__nfs4_get_acl_uncached" accidently dropped the checking for too small
result buffer length.
If someone uses getxattr on "system.nfs4_acl" on an NFSv4 mount
supporting ACLs, the ACL has not been cached and the buffer suplied is
too short, we still copy the complete ACL, resulting in kernel and user
space memory corruption.
Signed-off-by: Sven Wegener <sven.wegener@stealer.net>
Cc: stable@kernel.org
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs/nfs4proc.c')
| -rw-r--r-- | fs/nfs/nfs4proc.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 5eec4429970c..05e5f6f9f2b8 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -3937,8 +3937,13 @@ static ssize_t __nfs4_get_acl_uncached(struct inode *inode, void *buf, size_t bu goto out_free; } nfs4_write_cached_acl(inode, pages, res.acl_data_offset, res.acl_len); - if (buf) + if (buf) { + if (res.acl_len > buflen) { + ret = -ERANGE; + goto out_free; + } _copy_from_pages(buf, pages, res.acl_data_offset, res.acl_len); + } out_ok: ret = res.acl_len; out_free: |