commit: 7d3e91a89b7adbc2831334def9e494dd9892f9af From: Sven Wegener <[email protected]> Date: Sat, 8 Dec 2012 15:30:18 +0100 Subject: 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 <[email protected]> Cc: [email protected] Signed-off-by: Trond Myklebust <[email protected]> --- 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 5eec442..05e5f6f 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: -- 1.7.3.4 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
