Initialize the eb.vma array with values of 0 when the eb structure is
first set up. In particular, this sets the eb->vma[i].vma pointers to
NULL, simplifying cleanup and getting rid of the bug described below.
During the execution of eb_lookup_vmas(), the eb->vma array is
successively filled up with struct eb_vma objects. This process includes
calling eb_add_vma(), which might fail; however, even in the event of
failure, eb->vma[i].vma is set for the currently processed buffer.
If eb_add_vma() fails, eb_lookup_vmas() returns with an error, which
prompts a call to eb_release_vmas() to clean up the mess. Since
eb_lookup_vmas() might fail during processing any (possibly not first)
buffer, eb_release_vmas() checks whether a buffer's vma is NULL to know
at what point did the lookup function fail.
In eb_lookup_vmas(), eb->vma[i].vma is set to NULL if either the helper
function eb_lookup_vma() or eb_validate_vma() fails. eb->vma[i+1].vma is
set to NULL in case i915_gem_object_userptr_submit_init() fails; the
current one needs to be cleaned up by eb_release_vmas() at this point,
so the next one is set. If eb_add_vma() fails, neither the current nor
the next vma is nullified, which is a source of a NULL deref bug
described in the issue linked in the Closes tag.
When entering eb_lookup_vmas(), the vma pointers are set to the slab
poison value, instead of NULL. This doesn't matter for the actual
lookup, since it gets overwritten anyway, however the eb_release_vmas()
function only recognizes NULL as the stopping value, hence the pointers
are being nullified as they go in case of intermediate failure. This
patch changes the approach to filling them all with NULL at the start
instead, rather than handling that manually during failure.
Reported-by: Gangmin Kim <km.kim1503(a)gmail.com>
Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/15062
Fixes: 544460c33821 ("drm/i915: Multi-BB execbuf")
Cc: <stable(a)vger.kernel.org> # 5.16.x
Signed-off-by: Krzysztof Niemiec <krzysztof.niemiec(a)intel.com>
---
I messed up the continuity in previous revisions; the original patch
was sent as [1], and the first revision (which I didn't mark as v2 due
to the title change) was sent as [2].
This is the full current changelog:
v3:
- use memset() to fill the entire eb.vma array with zeros instead of
looping through the elements (Janusz)
- add a comment clarifying the mechanism of the initial allocation (Janusz)
- change the commit log again, including title
- rearrange the tags to keep checkpatch happy
v2:
- set the eb->vma[i].vma pointers to NULL during setup instead of
ad-hoc at failure (Janusz)
- romanize the reporter's name (Andi, offline)
- change the commit log, including title
[1] https://patchwork.freedesktop.org/series/156832/
[2] https://patchwork.freedesktop.org/series/158036/
.../gpu/drm/i915/gem/i915_gem_execbuffer.c | 36 +++++++++----------
1 file changed, 16 insertions(+), 20 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index b057c2fa03a4..5f2b736b53ab 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -951,13 +951,13 @@ static int eb_lookup_vmas(struct i915_execbuffer *eb)
vma = eb_lookup_vma(eb, eb->exec[i].handle);
if (IS_ERR(vma)) {
err = PTR_ERR(vma);
- goto err;
+ return err;
}
err = eb_validate_vma(eb, &eb->exec[i], vma);
if (unlikely(err)) {
i915_vma_put(vma);
- goto err;
+ return err;
}
err = eb_add_vma(eb, ¤t_batch, i, vma);
@@ -966,19 +966,8 @@ static int eb_lookup_vmas(struct i915_execbuffer *eb)
if (i915_gem_object_is_userptr(vma->obj)) {
err = i915_gem_object_userptr_submit_init(vma->obj);
- if (err) {
- if (i + 1 < eb->buffer_count) {
- /*
- * Execbuffer code expects last vma entry to be NULL,
- * since we already initialized this entry,
- * set the next value to NULL or we mess up
- * cleanup handling.
- */
- eb->vma[i + 1].vma = NULL;
- }
-
+ if (err)
return err;
- }
eb->vma[i].flags |= __EXEC_OBJECT_USERPTR_INIT;
eb->args->flags |= __EXEC_USERPTR_USED;
@@ -986,10 +975,6 @@ static int eb_lookup_vmas(struct i915_execbuffer *eb)
}
return 0;
-
-err:
- eb->vma[i].vma = NULL;
- return err;
}
static int eb_lock_vmas(struct i915_execbuffer *eb)
@@ -3375,7 +3360,9 @@ i915_gem_do_execbuffer(struct drm_device *dev,
eb.exec = exec;
eb.vma = (struct eb_vma *)(exec + args->buffer_count + 1);
- eb.vma[0].vma = NULL;
+
+ memset(eb.vma, 0x00, args->buffer_count * sizeof(struct eb_vma));
+
eb.batch_pool = NULL;
eb.invalid_flags = __EXEC_OBJECT_UNKNOWN_FLAGS;
@@ -3584,7 +3571,16 @@ i915_gem_execbuffer2_ioctl(struct drm_device *dev, void *data,
if (err)
return err;
- /* Allocate extra slots for use by the command parser */
+ /*
+ * Allocate extra slots for use by the command parser.
+ *
+ * Note that this allocation handles two different arrays (the
+ * exec2_list array, and the eventual eb.vma array introduced in
+ * i915_gem_do_execubuffer()), that reside in virtually contiguous
+ * memory. Also note that the allocation doesn't fill the area with
+ * zeros (the first part doesn't need to be), but the second part only
+ * is explicitly zeroed later in i915_gem_do_execbuffer().
+ */
exec2_list = kvmalloc_array(count + 2, eb_element_size(),
__GFP_NOWARN | GFP_KERNEL);
if (exec2_list == NULL) {
--
2.45.2
When nvmem_cell_read() fails in mt798x_phy_calibration(), the function
returns without calling nvmem_cell_put(), leaking the cell reference.
Move nvmem_cell_put() right after nvmem_cell_read() to ensure the cell
reference is always released regardless of the read result.
Found via static analysis and code review.
Fixes: 98c485eaf509 ("net: phy: add driver for MediaTek SoC built-in GE PHYs")
Cc: stable(a)vger.kernel.org
Signed-off-by: Miaoqian Lin <linmq006(a)gmail.com>
---
drivers/net/phy/mediatek/mtk-ge-soc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/phy/mediatek/mtk-ge-soc.c b/drivers/net/phy/mediatek/mtk-ge-soc.c
index cd09fbf92ef2..2c4bbc236202 100644
--- a/drivers/net/phy/mediatek/mtk-ge-soc.c
+++ b/drivers/net/phy/mediatek/mtk-ge-soc.c
@@ -1167,9 +1167,9 @@ static int mt798x_phy_calibration(struct phy_device *phydev)
}
buf = (u32 *)nvmem_cell_read(cell, &len);
+ nvmem_cell_put(cell);
if (IS_ERR(buf))
return PTR_ERR(buf);
- nvmem_cell_put(cell);
if (!buf[0] || !buf[1] || !buf[2] || !buf[3] || len < 4 * sizeof(u32)) {
phydev_err(phydev, "invalid efuse data\n");
--
2.25.1
Hi,
The following patch has already been merged into mainline (master) and
the linux-6.12.y stable branch:
net: lan743x: Allocate rings outside ZONE_DMA (commit
8a8f3f4991761a70834fe6719d09e9fd338a766e)
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id…https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=…
I believe this patch should be backported. Our customer is experiencing
an issue where a Microchip LAN7430 NIC fails to work in a crashkernel
environment.
Because the driver uses the ZONE_DMA flag, memory allocation fails when
crashkernel reserves memory — preventing the card from functioning,
especially when they try to transfer the VMcore file over network.
We are using older kernel versions and request that this fix be applied
to the following branches:
linux-6.1.y
linux-6.6.y
linux-6.12.y
Could you please help backport this fix?
Thank you for your time and support.
Best regards,
Liyin
We switched from (wrongly) using the page count to an independent
shared count. Now, shared page tables have a refcount of 1 (excluding
speculative references) and instead use ptdesc->pt_share_count to
identify sharing.
We didn't convert hugetlb_pmd_shared(), so right now, we would never
detect a shared PMD table as such, because sharing/unsharing no longer
touches the refcount of a PMD table.
Page migration, like mbind() or migrate_pages() would allow for migrating
folios mapped into such shared PMD tables, even though the folios are
not exclusive. In smaps we would account them as "private" although they
are "shared", and we would be wrongly setting the PM_MMAP_EXCLUSIVE in the
pagemap interface.
Fix it by properly using ptdesc_pmd_is_shared() in hugetlb_pmd_shared().
Fixes: 59d9094df3d7 ("mm: hugetlb: independent PMD page table shared count")
Cc: <stable(a)vger.kernel.org>
Cc: Liu Shixin <liushixin2(a)huawei.com>
Signed-off-by: David Hildenbrand (Red Hat) <david(a)kernel.org>
---
include/linux/hugetlb.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 019a1c5281e4e..03c8725efa289 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -1326,7 +1326,7 @@ static inline __init void hugetlb_cma_reserve(int order)
#ifdef CONFIG_HUGETLB_PMD_PAGE_TABLE_SHARING
static inline bool hugetlb_pmd_shared(pte_t *pte)
{
- return page_count(virt_to_page(pte)) > 1;
+ return ptdesc_pmd_is_shared(virt_to_ptdesc(pte));
}
#else
static inline bool hugetlb_pmd_shared(pte_t *pte)
--
2.52.0