From: Marta Rybczynska <rybczyn...@gmail.com> This patch adds a fix for a possible negative shift in grub's zfs. It is a part of a security series [1].
[1] https://lists.gnu.org/archive/html/grub-devel/2021-03/msg00007.html Signed-off-by: Marta Rybczynska <marta.rybczyn...@huawei.com> Signed-off-by: Steve Sakoman <st...@sakoman.com> --- ...ix-possible-negative-shift-operation.patch | 42 +++++++++++++++++++ meta/recipes-bsp/grub/grub2.inc | 1 + 2 files changed, 43 insertions(+) create mode 100644 meta/recipes-bsp/grub/files/0021-zfs-Fix-possible-negative-shift-operation.patch diff --git a/meta/recipes-bsp/grub/files/0021-zfs-Fix-possible-negative-shift-operation.patch b/meta/recipes-bsp/grub/files/0021-zfs-Fix-possible-negative-shift-operation.patch new file mode 100644 index 0000000000..12418858f9 --- /dev/null +++ b/meta/recipes-bsp/grub/files/0021-zfs-Fix-possible-negative-shift-operation.patch @@ -0,0 +1,42 @@ +From c757779e5d09719666c3b155afd2421978a107bd Mon Sep 17 00:00:00 2001 +From: Darren Kenny <darren.ke...@oracle.com> +Date: Tue, 24 Nov 2020 16:41:49 +0000 +Subject: [PATCH] zfs: Fix possible negative shift operation + +While it is possible for the return value from zfs_log2() to be zero +(0), it is quite unlikely, given that the previous assignment to blksz +is shifted up by SPA_MINBLOCKSHIFT (9) before 9 is subtracted at the +assignment to epbs. + +But, while unlikely during a normal operation, it may be that a carefully +crafted ZFS filesystem could result in a zero (0) value to the +dn_datalbkszsec field, which means that the shift left does nothing +and assigns zero (0) to blksz, resulting in a negative epbs value. + +Fixes: CID 73608 + +Signed-off-by: Darren Kenny <darren.ke...@oracle.com> +Reviewed-by: Daniel Kiper <daniel.ki...@oracle.com> + +Upstream-Status: Backport [https://git.savannah.gnu.org/cgit/grub.git/commit/?id=a02091834d3e167320d8a262ff04b8e83c5e616d] +Signed-off-by: Marta Rybczynska <marta.rybczyn...@huawei.com> +--- + grub-core/fs/zfs/zfs.c | 5 +++++ + 1 file changed, 5 insertions(+) + +diff --git a/grub-core/fs/zfs/zfs.c b/grub-core/fs/zfs/zfs.c +index 36d0373..0c42cba 100644 +--- a/grub-core/fs/zfs/zfs.c ++++ b/grub-core/fs/zfs/zfs.c +@@ -2667,6 +2667,11 @@ dnode_get (dnode_end_t * mdn, grub_uint64_t objnum, grub_uint8_t type, + blksz = grub_zfs_to_cpu16 (mdn->dn.dn_datablkszsec, + mdn->endian) << SPA_MINBLOCKSHIFT; + epbs = zfs_log2 (blksz) - DNODE_SHIFT; ++ ++ /* While this should never happen, we should check that epbs is not negative. */ ++ if (epbs < 0) ++ epbs = 0; ++ + blkid = objnum >> epbs; + idx = objnum & ((1 << epbs) - 1); + diff --git a/meta/recipes-bsp/grub/grub2.inc b/meta/recipes-bsp/grub/grub2.inc index 3c5274fd96..360e86685b 100644 --- a/meta/recipes-bsp/grub/grub2.inc +++ b/meta/recipes-bsp/grub/grub2.inc @@ -67,6 +67,7 @@ SRC_URI = "${GNU_MIRROR}/grub/grub-${PV}.tar.gz \ file://0018-disk-ldm-Fix-memory-leak-on-uninserted-lv-references.patch \ file://0019-disk-cryptodisk-Fix-potential-integer-overflow.patch \ file://0020-hfsplus-Check-that-the-volume-name-length-is-valid.patch \ + file://0021-zfs-Fix-possible-negative-shift-operation.patch \ " SRC_URI[md5sum] = "5ce674ca6b2612d8939b9e6abed32934" SRC_URI[sha256sum] = "f10c85ae3e204dbaec39ae22fa3c5e99f0665417e91c2cb49b7e5031658ba6ea" -- 2.25.1
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