3.7-stable review patch. If anyone has any objections, please let me know.
------------------ From: Sven Wegener <[email protected]> commit 7d3e91a89b7adbc2831334def9e494dd9892f9af upstream. 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]> Signed-off-by: Trond Myklebust <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- fs/nfs/nfs4proc.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -3937,8 +3937,13 @@ static ssize_t __nfs4_get_acl_uncached(s 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: -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
