diff --git a/0005-Fix-XFS-directory-extent-parsing.patch b/0005-Fix-XFS-directory-extent-parsing.patch new file mode 100644 index 0000000..e665262 --- /dev/null +++ b/0005-Fix-XFS-directory-extent-parsing.patch @@ -0,0 +1,162 @@ +The XFS directory entry parsing code has never been completely correct +for extent based directories. The parser correctly handles the case +where the directory is contained in a single extent, but then mistakenly +assumes the data blocks for the multiple extent case are each identical +to the single extent case. The difference in the format of the data +blocks between the two cases is tiny enough that its gone unnoticed for +a very long time. + +A recent change introduced some additional bounds checking into the XFS +parser. Like GRUB's existing parser, it is correct for the single extent +case but incorrect for the multiple extent case. When parsing a +directory with multiple extents, this new bounds checking is sometimes +(but not always) tripped and triggers an "invalid XFS diretory entry" +error. This probably would have continued to go unnoticed but the +/boot/grub/ directory is large enough that it often has multiple +extents. + +The difference between the two cases is that when there are multiple +extents, the data blocks do not contain a trailer nor do they contain +any leaf information. That information is stored in a separate set of +extents dedicated to just the leaf information. These extents come after +the directory entry extents and are not included in the inode size. So +the existing parser already ignores the leaf extents. + +The only reason to read the trailer/leaf information at all is so that +the parser can avoid misinterpreting that data as directory entries. So +this updates the parser as follows: + +For the single extent case the parser doesn't change much: +1. Read the size of the leaf information from the trailer +2. Set the end pointer for the parser to the start of the leaf + information. (The previous bounds checking set the end pointer to the + start of the trailer, so this is actually a small improvement.) +3. Set the entries variable to the expected number of directory entries. + +For the multiple extent case: +1. Set the end pointer to the end of the block. +2. Do not set up the entries variable. Figuring out how many entries are + in each individual block is complex and does not seem worth it when + it appears to be safe to just iterate over the entire block. + +Notes: +* When there is only one extent there will only ever be one block. If + more than one block is required then XFS will always switch to holding + leaf information in a separate extent. +* B-tree based directories seems to be parsed properly by the same code + that handles multiple extents. This is unlikely to ever occur within + /boot though because its only used when there are an extremely large + number of directory entries. + +Fixes: ef7850c75 (fs/xfs: Fix issues found while fuzzing the XFS filesystem) +Fixes: b2499b29c (Adds support for the XFS filesystem.) +Fixes: https://savannah.gnu.org/bugs/?64376 + +Signed-off-by: Jon DeVree +--- + +Notes: + Changes from v2: + * Fix bounds check on filename + + Changes from v1: + * Address review feedback + + grub-core/fs/xfs.c | 51 +++++++++++++++++++++++++++++++++------------- + 1 file changed, 37 insertions(+), 14 deletions(-) + +diff --git a/grub-core/fs/xfs.c b/grub-core/fs/xfs.c +index b91cd32b4..cc3b892a3 100644 +--- a/grub-core/fs/xfs.c ++++ b/grub-core/fs/xfs.c +@@ -223,6 +223,12 @@ struct grub_xfs_inode + /* Size of struct grub_xfs_inode v2, up to unused4 member included. */ + #define XFS_V2_INODE_SIZE (XFS_V3_INODE_SIZE - 76) + ++struct grub_xfs_dir_leaf_entry ++{ ++ grub_uint32_t hashval; ++ grub_uint32_t address; ++} GRUB_PACKED; ++ + struct grub_xfs_dirblock_tail + { + grub_uint32_t leaf_count; +@@ -877,9 +883,8 @@ grub_xfs_iterate_dir (grub_fshelp_node_t dir, + { + struct grub_xfs_dir2_entry *direntry = + grub_xfs_first_de(dir->data, dirblock); +- int entries; +- struct grub_xfs_dirblock_tail *tail = +- grub_xfs_dir_tail(dir->data, dirblock); ++ int entries = -1; ++ char *end = dirblock + dirblk_size; + + numread = grub_xfs_read_file (dir, 0, 0, + blk << dirblk_log2, +@@ -890,14 +895,27 @@ grub_xfs_iterate_dir (grub_fshelp_node_t dir, + return 0; + } + +- entries = (grub_be_to_cpu32 (tail->leaf_count) +- - grub_be_to_cpu32 (tail->leaf_stale)); ++ /* leaf and tail information are only in the data block if the number ++ * of extents is 1 */ ++ if (dir->inode.nextents == grub_cpu_to_be32_compile_time (1)) ++ { ++ struct grub_xfs_dirblock_tail *tail = ++ grub_xfs_dir_tail(dir->data, dirblock); ++ end = (char *)tail; ++ ++ /* subtract the space used by leaf nodes */ ++ end -= grub_be_to_cpu32 (tail->leaf_count) * ++ sizeof (struct grub_xfs_dir_leaf_entry); ++ ++ entries = (grub_be_to_cpu32 (tail->leaf_count) ++ - grub_be_to_cpu32 (tail->leaf_stale)); + +- if (!entries) +- continue; ++ if (!entries) ++ continue; ++ } + + /* Iterate over all entries within this block. */ +- while ((char *)direntry < (char *)tail) ++ while ((char *)direntry < (char *)end) + { + grub_uint8_t *freetag; + char *filename; +@@ -917,7 +935,7 @@ grub_xfs_iterate_dir (grub_fshelp_node_t dir, + } + + filename = (char *)(direntry + 1); +- if (filename + direntry->len - 1 > (char *) tail) ++ if (filename + direntry->len + 1 > (char *) end) + return grub_error (GRUB_ERR_BAD_FS, "invalid XFS directory entry"); + + /* The byte after the filename is for the filetype, padding, or +@@ -931,11 +949,16 @@ grub_xfs_iterate_dir (grub_fshelp_node_t dir, + return 1; + } + +- /* Check if last direntry in this block is +- reached. */ +- entries--; +- if (!entries) +- break; ++ /* the expected number of directory entries is only tracked for the ++ * single extent case */ ++ if (dir->inode.nextents == grub_cpu_to_be32_compile_time (1)) ++ { ++ /* Check if last direntry in this block is ++ reached. */ ++ entries--; ++ if (!entries) ++ break; ++ } + + /* Select the next directory entry. */ + direntry = grub_xfs_next_de(dir->data, direntry); +-- +2.40.1 diff --git a/PKGBUILD b/PKGBUILD index 4aefa8d..bfa18dc 100644 --- a/PKGBUILD +++ b/PKGBUILD @@ -64,6 +64,7 @@ source=("git+https://git.savannah.gnu.org/git/grub.git#tag=${_tag}?signed" '0002-10_linux-detect-archlinux-initramfs.patch' '0003-support-dropins-for-default-configuration.patch' '0004-ntfs-module-security.patch' + '0005-Fix-XFS-directory-extent-parsing.patch' 'grub.default' 'sbat.csv') @@ -71,6 +72,7 @@ sha256sums=('SKIP' 'SKIP' '912834ab9cd372f300541894615f910af4db82477c91b236674057eadfc76429' 'SKIP' + 'cb8c461662c69f1c65a196ec65bf9422269fa6b804fd43529c0307a5140dcbb1' '5dee6628c48eef79812bb9e86ee772068d85e7fcebbd2b2b8d1e19d24eda9dab' '8488aec30a93e8fe66c23ef8c23aefda39c38389530e9e73ba3fbcc8315d244d' 'b5d9fcd62ffb3c3950fdeb7089ec2dc2294ac52e9861980ad90a437dedbd3d47' @@ -137,6 +139,9 @@ prepare() { echo "Patch to fix ntfs module security vulnerabilities" patch -Np1 -i "${srcdir}/0004-ntfs-module-security.patch" + echo "Patch to fix XFS directory extent parsing" + patch -Np1 -i "${srcdir}/0005-Fix-XFS-directory-extent-parsing.patch" + echo "Fix DejaVuSans.ttf location so that grub-mkfont can create *.pf2 files for starfield theme..." sed 's|/usr/share/fonts/dejavu|/usr/share/fonts/dejavu /usr/share/fonts/TTF|g' -i "configure.ac"