From: Theodore Ts'o Date: Mon, 15 Feb 2021 04:51:45 +0000 (-0500) Subject: libext2fs: fix crash when ext2fs_mmp_stop() is called before MMP is initialized X-Git-Tag: v1.46.2~29 X-Git-Url: https://git.whamcloud.com/?a=commitdiff_plain;h=71f9bf7b08f2f7b632323719a4e69e94e0567a70;p=tools%2Fe2fsprogs.git libext2fs: fix crash when ext2fs_mmp_stop() is called before MMP is initialized The fatal_error() function in e2fsck can call ext2fs_mmp_stop() on a file system where MMP hasn't yet been initialized. When that happens, instead of crashing, have ext2fs_mmp_stop() return success, since mmp doesn't need to be stopped if it hasn't even been initialized yet. Addresses-Debian-Bug: #696609 Signed-off-by: Theodore Ts'o --- diff --git a/lib/ext2fs/mmp.c b/lib/ext2fs/mmp.c index c21ae27..023dccf 100644 --- a/lib/ext2fs/mmp.c +++ b/lib/ext2fs/mmp.c @@ -403,7 +403,8 @@ errcode_t ext2fs_mmp_stop(ext2_filsys fs) errcode_t retval = 0; if (!ext2fs_has_feature_mmp(fs->super) || - !(fs->flags & EXT2_FLAG_RW) || (fs->flags & EXT2_FLAG_SKIP_MMP)) + !(fs->flags & EXT2_FLAG_RW) || (fs->flags & EXT2_FLAG_SKIP_MMP) || + (fs->mmp_buf == NULL) || (fs->mmp_cmp == NULL)) goto mmp_error; retval = ext2fs_mmp_read(fs, fs->super->s_mmp_block, fs->mmp_buf);