From 7127be29378b1230eb8dd8b84f18d6b69c56e959 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Tue, 15 Aug 2006 13:56:26 +0200 Subject: Fix possible UDF deadlock and memory corruption (CVE-2006-4145) UDF code is not really ready to handle extents larger that 1GB. This is the easy way to forbid creating those. Also truncation code did not count with the case when there are no extents in the file and we are extending the file. Signed-off-by: Jan Kara Signed-off-by: Greg Kroah-Hartman --- fs/udf/super.c | 2 +- fs/udf/truncate.c | 64 +++++++++++++++++++++++++++++++++---------------------- 2 files changed, 40 insertions(+), 26 deletions(-) diff --git a/fs/udf/super.c b/fs/udf/super.c index e45789fe38e..73fc0d8ae8b 100644 --- a/fs/udf/super.c +++ b/fs/udf/super.c @@ -1653,7 +1653,7 @@ static int udf_fill_super(struct super_block *sb, void *options, int silent) iput(inode); goto error_out; } - sb->s_maxbytes = MAX_LFS_FILESIZE; + sb->s_maxbytes = 1<<30; return 0; error_out: diff --git a/fs/udf/truncate.c b/fs/udf/truncate.c index e1b0e8cfecb..0abd66ce36e 100644 --- a/fs/udf/truncate.c +++ b/fs/udf/truncate.c @@ -239,37 +239,51 @@ void udf_truncate_extents(struct inode * inode) { if (offset) { - extoffset -= adsize; - etype = udf_next_aext(inode, &bloc, &extoffset, &eloc, &elen, &bh, 1); - if (etype == (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30)) - { - extoffset -= adsize; - elen = EXT_NOT_RECORDED_NOT_ALLOCATED | (elen + offset); - udf_write_aext(inode, bloc, &extoffset, eloc, elen, bh, 0); + /* + * OK, there is not extent covering inode->i_size and + * no extent above inode->i_size => truncate is + * extending the file by 'offset'. + */ + if ((!bh && extoffset == udf_file_entry_alloc_offset(inode)) || + (bh && extoffset == sizeof(struct allocExtDesc))) { + /* File has no extents at all! */ + memset(&eloc, 0x00, sizeof(kernel_lb_addr)); + elen = EXT_NOT_RECORDED_NOT_ALLOCATED | offset; + udf_add_aext(inode, &bloc, &extoffset, eloc, elen, &bh, 1); } - else if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) - { - kernel_lb_addr neloc = { 0, 0 }; + else { extoffset -= adsize; - nelen = EXT_NOT_RECORDED_NOT_ALLOCATED | - ((elen + offset + inode->i_sb->s_blocksize - 1) & - ~(inode->i_sb->s_blocksize - 1)); - udf_write_aext(inode, bloc, &extoffset, neloc, nelen, bh, 1); - udf_add_aext(inode, &bloc, &extoffset, eloc, (etype << 30) | elen, &bh, 1); - } - else - { - if (elen & (inode->i_sb->s_blocksize - 1)) + etype = udf_next_aext(inode, &bloc, &extoffset, &eloc, &elen, &bh, 1); + if (etype == (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30)) + { + extoffset -= adsize; + elen = EXT_NOT_RECORDED_NOT_ALLOCATED | (elen + offset); + udf_write_aext(inode, bloc, &extoffset, eloc, elen, bh, 0); + } + else if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) { + kernel_lb_addr neloc = { 0, 0 }; extoffset -= adsize; - elen = EXT_RECORDED_ALLOCATED | - ((elen + inode->i_sb->s_blocksize - 1) & + nelen = EXT_NOT_RECORDED_NOT_ALLOCATED | + ((elen + offset + inode->i_sb->s_blocksize - 1) & ~(inode->i_sb->s_blocksize - 1)); - udf_write_aext(inode, bloc, &extoffset, eloc, elen, bh, 1); + udf_write_aext(inode, bloc, &extoffset, neloc, nelen, bh, 1); + udf_add_aext(inode, &bloc, &extoffset, eloc, (etype << 30) | elen, &bh, 1); + } + else + { + if (elen & (inode->i_sb->s_blocksize - 1)) + { + extoffset -= adsize; + elen = EXT_RECORDED_ALLOCATED | + ((elen + inode->i_sb->s_blocksize - 1) & + ~(inode->i_sb->s_blocksize - 1)); + udf_write_aext(inode, bloc, &extoffset, eloc, elen, bh, 1); + } + memset(&eloc, 0x00, sizeof(kernel_lb_addr)); + elen = EXT_NOT_RECORDED_NOT_ALLOCATED | offset; + udf_add_aext(inode, &bloc, &extoffset, eloc, elen, &bh, 1); } - memset(&eloc, 0x00, sizeof(kernel_lb_addr)); - elen = EXT_NOT_RECORDED_NOT_ALLOCATED | offset; - udf_add_aext(inode, &bloc, &extoffset, eloc, elen, &bh, 1); } } } -- cgit v1.2.3-18-g5258