grub: add a fix for a memory leak

This patch adds a fix for a memory leak in grub's path construction
in zfs. It is a part of a security series [1].

[1] https://lists.gnu.org/archive/html/grub-devel/2021-03/msg00007.html

(From OE-Core rev: f2a474545b8ba61a43fcbcd3c375c5db9f0303ca)

Signed-off-by: Marta Rybczynska <marta.rybczynska@huawei.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
This commit is contained in:
Marta Rybczynska
2022-02-18 11:05:30 +01:00
committed by Richard Purdie
parent b461e69025
commit 0dd3f436f4
2 changed files with 122 additions and 0 deletions

View File

@@ -0,0 +1,121 @@
From 83fdffc07ec4586b375ab36189f255ffbd8f99c2 Mon Sep 17 00:00:00 2001
From: Paulo Flabiano Smorigo <pfsmorigo@canonical.com>
Date: Mon, 14 Dec 2020 18:54:49 -0300
Subject: [PATCH] zfs: Fix resource leaks while constructing path
There are several exit points in dnode_get_path() that are causing possible
memory leaks.
In the while(1) the correct exit mechanism should not be to do a direct return,
but to instead break out of the loop, setting err first if it is not already set.
The reason behind this is that the dnode_path is a linked list, and while doing
through this loop, it is being allocated and built up - the only way to
correctly unravel it is to traverse it, which is what is being done at the end
of the function outside of the loop.
Several of the existing exit points correctly did a break, but not all so this
change makes that more consistent and should resolve the leaking of memory as
found by Coverity.
Fixes: CID 73741
Signed-off-by: Paulo Flabiano Smorigo <pfsmorigo@canonical.com>
Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Upstream-Status: Backport [https://git.savannah.gnu.org/cgit/grub.git/commit/?id=89bdab965805e8d54d7f75349024e1a11cbe2eb8]
Signed-off-by: Marta Rybczynska <marta.rybczynska@huawei.com>
---
grub-core/fs/zfs/zfs.c | 30 +++++++++++++++++++++---------
1 file changed, 21 insertions(+), 9 deletions(-)
diff --git a/grub-core/fs/zfs/zfs.c b/grub-core/fs/zfs/zfs.c
index 0c42cba..9087a72 100644
--- a/grub-core/fs/zfs/zfs.c
+++ b/grub-core/fs/zfs/zfs.c
@@ -2836,8 +2836,8 @@ dnode_get_path (struct subvolume *subvol, const char *path_in, dnode_end_t *dn,
if (dnode_path->dn.dn.dn_type != DMU_OT_DIRECTORY_CONTENTS)
{
- grub_free (path_buf);
- return grub_error (GRUB_ERR_BAD_FILE_TYPE, N_("not a directory"));
+ err = grub_error (GRUB_ERR_BAD_FILE_TYPE, N_("not a directory"));
+ break;
}
err = zap_lookup (&(dnode_path->dn), cname, &objnum,
data, subvol->case_insensitive);
@@ -2879,11 +2879,18 @@ dnode_get_path (struct subvolume *subvol, const char *path_in, dnode_end_t *dn,
<< SPA_MINBLOCKSHIFT);
if (blksz == 0)
- return grub_error(GRUB_ERR_BAD_FS, "0-sized block");
+ {
+ err = grub_error (GRUB_ERR_BAD_FS, "0-sized block");
+ break;
+ }
sym_value = grub_malloc (sym_sz);
if (!sym_value)
- return grub_errno;
+ {
+ err = grub_errno;
+ break;
+ }
+
for (block = 0; block < (sym_sz + blksz - 1) / blksz; block++)
{
void *t;
@@ -2893,7 +2900,7 @@ dnode_get_path (struct subvolume *subvol, const char *path_in, dnode_end_t *dn,
if (err)
{
grub_free (sym_value);
- return err;
+ break;
}
movesize = sym_sz - block * blksz;
@@ -2903,6 +2910,8 @@ dnode_get_path (struct subvolume *subvol, const char *path_in, dnode_end_t *dn,
grub_memcpy (sym_value + block * blksz, t, movesize);
grub_free (t);
}
+ if (err)
+ break;
free_symval = 1;
}
path = path_buf = grub_malloc (sym_sz + grub_strlen (oldpath) + 1);
@@ -2911,7 +2920,8 @@ dnode_get_path (struct subvolume *subvol, const char *path_in, dnode_end_t *dn,
grub_free (oldpathbuf);
if (free_symval)
grub_free (sym_value);
- return grub_errno;
+ err = grub_errno;
+ break;
}
grub_memcpy (path, sym_value, sym_sz);
if (free_symval)
@@ -2949,11 +2959,12 @@ dnode_get_path (struct subvolume *subvol, const char *path_in, dnode_end_t *dn,
err = zio_read (bp, dnode_path->dn.endian, &sahdrp, NULL, data);
if (err)
- return err;
+ break;
}
else
{
- return grub_error (GRUB_ERR_BAD_FS, "filesystem is corrupt");
+ err = grub_error (GRUB_ERR_BAD_FS, "filesystem is corrupt");
+ break;
}
hdrsize = SA_HDR_SIZE (((sa_hdr_phys_t *) sahdrp));
@@ -2974,7 +2985,8 @@ dnode_get_path (struct subvolume *subvol, const char *path_in, dnode_end_t *dn,
if (!path_buf)
{
grub_free (oldpathbuf);
- return grub_errno;
+ err = grub_errno;
+ break;
}
grub_memcpy (path, sym_value, sym_sz);
path [sym_sz] = 0;

View File

@@ -68,6 +68,7 @@ SRC_URI = "${GNU_MIRROR}/grub/grub-${PV}.tar.gz \
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 \
file://0022-zfs-Fix-resource-leaks-while-constructing-path.patch \
"
SRC_URI[md5sum] = "5ce674ca6b2612d8939b9e6abed32934"
SRC_URI[sha256sum] = "f10c85ae3e204dbaec39ae22fa3c5e99f0665417e91c2cb49b7e5031658ba6ea"