From ecbb903c56745d59c301db26dd7d8b74b520eb84 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Tue, 11 Jul 2017 17:54:35 -0400 Subject: [PATCH] NFS: Be more careful about mapping file permissions When mapping a directory, we want the MAY_WRITE permissions to reflect whether or not we have permission to modify, add and delete the directory entries. MAY_EXEC must map to lookup permissions. On the other hand, for files, we want MAY_WRITE to reflect a permission to modify and extend the file. Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker --- fs/nfs/dir.c | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-) diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 8fae8b00b8f5..37a6180ee2e8 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -2379,21 +2379,30 @@ EXPORT_SYMBOL_GPL(nfs_access_add_cache); #define NFS_MAY_WRITE (NFS4_ACCESS_MODIFY | \ NFS4_ACCESS_EXTEND | \ NFS4_ACCESS_DELETE) +#define NFS_FILE_MAY_WRITE (NFS4_ACCESS_MODIFY | \ + NFS4_ACCESS_EXTEND) +#define NFS_DIR_MAY_WRITE NFS_MAY_WRITE #define NFS_MAY_LOOKUP (NFS4_ACCESS_LOOKUP) #define NFS_MAY_EXECUTE (NFS4_ACCESS_EXECUTE) static int -nfs_access_calc_mask(u32 access_result) +nfs_access_calc_mask(u32 access_result, umode_t umode) { int mask = 0; if (access_result & NFS_MAY_READ) mask |= MAY_READ; - if (access_result & NFS_MAY_WRITE) - mask |= MAY_WRITE; - if (access_result & NFS_MAY_LOOKUP) - mask |= MAY_EXEC; - if (access_result & NFS_MAY_EXECUTE) - mask |= MAY_EXEC; + if (S_ISDIR(umode)) { + if ((access_result & NFS_DIR_MAY_WRITE) == NFS_DIR_MAY_WRITE) + mask |= MAY_WRITE; + if ((access_result & NFS_MAY_LOOKUP) == NFS_MAY_LOOKUP) + mask |= MAY_EXEC; + } else if (S_ISREG(umode)) { + if ((access_result & NFS_FILE_MAY_WRITE) == NFS_FILE_MAY_WRITE) + mask |= MAY_WRITE; + if ((access_result & NFS_MAY_EXECUTE) == NFS_MAY_EXECUTE) + mask |= MAY_EXEC; + } else if (access_result & NFS_MAY_WRITE) + mask |= MAY_WRITE; return mask; } @@ -2438,7 +2447,7 @@ static int nfs_do_access(struct inode *inode, struct rpc_cred *cred, int mask) } nfs_access_add_cache(inode, &cache); out_cached: - cache_mask = nfs_access_calc_mask(cache.mask); + cache_mask = nfs_access_calc_mask(cache.mask, inode->i_mode); if ((mask & ~cache_mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) != 0) status = -EACCES; out: -- 2.39.2