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| author | Niu Yawei <niu@whamcloud.com> | 2011-11-19 23:08:03 -0500 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2011-11-19 23:11:20 -0500 |
| commit | 08ae93a2eda03817deabf08d4da9015a283ed56b (patch) | |
| tree | 6eae7f64b209021229be882aa26c0186fb81cf0b /lib/ext2fs | |
| parent | 19ef479acf566343b277be3554beda7e1f400381 (diff) | |
| download | e2fsprogs-08ae93a2eda03817deabf08d4da9015a283ed56b.tar.gz | |
libext2fs: enforce a max nested link count in ext2fs_find_block_device()
Define EXT2FS_MAX_NESTED_LINKS as 8, and check the link count to make
sure we don't exceed it in ext2fs_find_block_device() and
follow_link(). This fixes a potential infinite loop in
ext2fs_find_block_device() if there are symbolic loop links in the
device directory.
Signed-off-by: Niu Yawei <niu@whamcloud.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'lib/ext2fs')
| -rw-r--r-- | lib/ext2fs/ext2fsP.h | 2 | ||||
| -rw-r--r-- | lib/ext2fs/finddev.c | 5 | ||||
| -rw-r--r-- | lib/ext2fs/namei.c | 5 |
3 files changed, 10 insertions, 2 deletions
diff --git a/lib/ext2fs/ext2fsP.h b/lib/ext2fs/ext2fsP.h index b182d7fe..82e1ba0e 100644 --- a/lib/ext2fs/ext2fsP.h +++ b/lib/ext2fs/ext2fsP.h @@ -11,6 +11,8 @@ #include "ext2fs.h" +#define EXT2FS_MAX_NESTED_LINKS 8 + /* * Badblocks list */ diff --git a/lib/ext2fs/finddev.c b/lib/ext2fs/finddev.c index 13ef14bf..311608de 100644 --- a/lib/ext2fs/finddev.c +++ b/lib/ext2fs/finddev.c @@ -34,6 +34,7 @@ #include "ext2_fs.h" #include "ext2fs.h" +#include "ext2fsP.h" struct dir_list { char *name; @@ -128,6 +129,7 @@ char *ext2fs_find_block_device(dev_t device) struct dir_list *list = 0, *new_list = 0; struct dir_list *current; char *ret_path = 0; + int level = 0; /* * Add the starting directories to search... @@ -154,6 +156,9 @@ char *ext2fs_find_block_device(dev_t device) if (list == 0) { list = new_list; new_list = 0; + /* Avoid infinite loop */ + if (++level >= EXT2FS_MAX_NESTED_LINKS) + break; } } free_dirlist(&list); diff --git a/lib/ext2fs/namei.c b/lib/ext2fs/namei.c index 6bbb1240..efcc02b7 100644 --- a/lib/ext2fs/namei.c +++ b/lib/ext2fs/namei.c @@ -20,6 +20,7 @@ #include "ext2_fs.h" #include "ext2fs.h" +#include "ext2fsP.h" static errcode_t open_namei(ext2_filsys fs, ext2_ino_t root, ext2_ino_t base, const char *pathname, size_t pathlen, int follow, @@ -45,9 +46,9 @@ static errcode_t follow_link(ext2_filsys fs, ext2_ino_t root, ext2_ino_t dir, *res_inode = inode; return 0; } - if (link_count++ > 5) { + if (link_count++ >= EXT2FS_MAX_NESTED_LINKS) return EXT2_ET_SYMLINK_LOOP; - } + /* FIXME-64: Actually, this is FIXME EXTENTS */ if (ext2fs_inode_data_blocks(fs,&ei)) { retval = ext2fs_get_mem(fs->blocksize, &buffer); |