LU-1540 e2fsck: add missing symlink NUL terminator

[tools/e2fsprogs.git] / e2fsck / pass1.c

diff --git a/e2fsck/pass1.c b/e2fsck/pass1.c
index 65fbdc9..fa14f0c 100644 (file)
--- a/e2fsck/pass1.c
+++ b/e2fsck/pass1.c
@@ -181,11 +181,12 @@ int e2fsck_pass1_check_device_inode(ext2_filsys fs EXT2FS_ATTR((unused)),
  * Check to make sure a symlink inode is real.  Returns 1 if the symlink
  * checks out, 0 if not.
  */
-int e2fsck_pass1_check_symlink(ext2_filsys fs, ext2_ino_t ino,
-                              struct ext2_inode *inode, char *buf)
+static int check_symlink(e2fsck_t ctx, struct problem_context *pctx,
+                        ext2_ino_t ino, struct ext2_inode *inode, char *buf)
 {
        unsigned int buflen;
        unsigned int len;
+       blk64_t blk;
 
        if ((inode->i_size_high || inode->i_size == 0) ||
            (inode->i_flags & EXT2_INDEX_FL))
@@ -196,7 +197,7 @@ int e2fsck_pass1_check_symlink(ext2_filsys fs, ext2_ino_t ino,
 
                if (inode->i_flags & EXT4_EXTENTS_FL)
                        return 0;
-               if (ext2fs_inline_data_size(fs, ino, &inline_size))
+               if (ext2fs_inline_data_size(ctx->fs, ino, &inline_size))
                        return 0;
                if (inode->i_size != inline_size)
                        return 0;
@@ -213,11 +214,10 @@ int e2fsck_pass1_check_symlink(ext2_filsys fs, ext2_ino_t ino,
                ext2_extent_handle_t    handle;
                struct ext2_extent_info info;
                struct ext2fs_extent    extent;
-               blk64_t blk;
                int i;
 
                if (inode->i_flags & EXT4_EXTENTS_FL) {
-                       if (ext2fs_extent_open2(fs, ino, inode, &handle))
+                       if (ext2fs_extent_open2(ctx->fs, ino, inode, &handle))
                                return 0;
                        if (ext2fs_extent_get_info(handle, &info) ||
                            (info.num_entries != 1) ||
@@ -242,29 +242,53 @@ int e2fsck_pass1_check_symlink(ext2_filsys fs, ext2_ino_t ino,
                                        return 0;
                }
 
-               if (blk < fs->super->s_first_data_block ||
-                   blk >= ext2fs_blocks_count(fs->super))
+               if (blk < ctx->fs->super->s_first_data_block ||
+                   blk >= ext2fs_blocks_count(ctx->fs->super))
                        return 0;
 
-               if (io_channel_read_blk64(fs->io, blk, 1, buf))
+               if (io_channel_read_blk64(ctx->fs->io, blk, 1, buf))
                        return 0;
 
-               buflen = fs->blocksize;
+               buflen = ctx->fs->blocksize;
        }
 
        if (inode->i_flags & EXT4_ENCRYPT_FL)
                len = ext2fs_le16_to_cpu(*(__u16 *)buf) + 2;
-       else
+       else {
                len = strnlen(buf, buflen);
 
+               /* Add missing NUL terminator at end of symlink (LU-1540),
+                * but only offer to fix this in pass1, not from pass2. */
+               if (len > inode->i_size && pctx != NULL &&
+                   fix_problem(ctx, PR_1_SYMLINK_NUL, pctx)) {
+                       buf[inode->i_size] = '\0';
+                       if (ext2fs_is_fast_symlink(inode)) {
+                               e2fsck_write_inode(ctx, ino,
+                                                  inode, "check_ext_attr");
+                       } else {
+                               if (io_channel_write_blk64(ctx->fs->io,
+                                                          blk, 1, buf))
+                                       return 0;
+                       }
+                       len = inode->i_size;
+               }
+       }
+
        if (len >= buflen)
                return 0;
 
        if (len != inode->i_size)
                return 0;
+
        return 1;
 }
 
+int e2fsck_pass1_check_symlink(e2fsck_t ctx, ext2_ino_t ino,
+                              struct ext2_inode *inode, char *buf)
+{
+       return check_symlink(ctx, NULL, ino, inode, buf);
+}
+
 /*
  * If the extents or inlinedata flags are set on the inode, offer to clear 'em.
  */
@@ -2064,8 +2088,7 @@ void e2fsck_pass1(e2fsck_t ctx)
                        check_size(ctx, &pctx);
                        ctx->fs_blockdev_count++;
                } else if (LINUX_S_ISLNK (inode->i_mode) &&
-                          e2fsck_pass1_check_symlink(fs, ino, inode,
-                                                     block_buf)) {
+                          check_symlink(ctx, &pctx, ino, inode, block_buf)) {
                        check_immutable(ctx, &pctx);
                        ctx->fs_symlinks_count++;
                        if (inode->i_flags & EXT4_INLINE_DATA_FL) {