lkml.org 
[lkml]   [2020]   [May]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.14 047/114] f2fs: fix to avoid memory leakage in f2fs_listxattr
    Date
    From: Randall Huang <huangrandall@google.com>

    commit 688078e7f36c293dae25b338ddc9e0a2790f6e06 upstream.

    In f2fs_listxattr, there is no boundary check before
    memcpy e_name to buffer.
    If the e_name_len is corrupted,
    unexpected memory contents may be returned to the buffer.

    Signed-off-by: Randall Huang <huangrandall@google.com>
    Reviewed-by: Chao Yu <yuchao0@huawei.com>
    Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
    [bwh: Backported to 4.14: Use f2fs_msg() instead of f2fs_err()]
    Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    ---
    fs/f2fs/xattr.c | 15 ++++++++++++++-
    1 file changed, 14 insertions(+), 1 deletion(-)

    --- a/fs/f2fs/xattr.c
    +++ b/fs/f2fs/xattr.c
    @@ -516,8 +516,9 @@ out:
    ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
    {
    struct inode *inode = d_inode(dentry);
    + nid_t xnid = F2FS_I(inode)->i_xattr_nid;
    struct f2fs_xattr_entry *entry;
    - void *base_addr;
    + void *base_addr, *last_base_addr;
    int error = 0;
    size_t rest = buffer_size;

    @@ -527,6 +528,8 @@ ssize_t f2fs_listxattr(struct dentry *de
    if (error)
    return error;

    + last_base_addr = (void *)base_addr + XATTR_SIZE(xnid, inode);
    +
    list_for_each_xattr(entry, base_addr) {
    const struct xattr_handler *handler =
    f2fs_xattr_handler(entry->e_name_index);
    @@ -534,6 +537,16 @@ ssize_t f2fs_listxattr(struct dentry *de
    size_t prefix_len;
    size_t size;

    + if ((void *)(entry) + sizeof(__u32) > last_base_addr ||
    + (void *)XATTR_NEXT_ENTRY(entry) > last_base_addr) {
    + f2fs_msg(dentry->d_sb, KERN_ERR,
    + "inode (%lu) has corrupted xattr",
    + inode->i_ino);
    + set_sbi_flag(F2FS_I_SB(inode), SBI_NEED_FSCK);
    + error = -EFSCORRUPTED;
    + goto cleanup;
    + }
    +
    if (!handler || (handler->list && !handler->list(dentry)))
    continue;


    \
     
     \ /
      Last update: 2020-05-18 20:25    [W:2.512 / U:1.848 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site