- Linux-stable-mirror - lists.linaro.org

[PATCH v7 1/3] drm/buddy: Optimize free block management with RB tree

by Arunpravin Paneer Selvam

Replace the freelist (O(n)) used for free block management with a red-black tree, providing more efficient O(log n) search, insert, and delete operations. This improves scalability and performance when managing large numbers of free blocks per order (e.g., hundreds or thousands). In the VK-CTS memory stress subtest, the buddy manager merges fragmented memory and inserts freed blocks into the freelist. Since freelist insertion is O(n), this becomes a bottleneck as fragmentation increases. Benchmarking shows list_insert_sorted() consumes ~52.69% CPU with the freelist, compared to just 0.03% with the RB tree (rbtree_insert.isra.0), despite performing the same sorted insert. This also improves performance in heavily fragmented workloads, such as games or graphics tests that stress memory. As the buddy allocator evolves with new features such as clear-page tracking, the resulting fragmentation and complexity have grown. These RB-tree based design changes are introduced to address that growth and ensure the allocator continues to perform efficiently under fragmented conditions. The RB tree implementation with separate clear/dirty trees provides: - O(n log n) aggregate complexity for all operations instead of O(n^2) - Elimination of soft lockups and system instability - Improved code maintainability and clarity - Better scalability for large memory systems - Predictable performance under fragmentation v3(Matthew): - Remove RB_EMPTY_NODE check in force_merge function. - Rename rb for loop macros to have less generic names and move to .c file. - Make the rb node rb and link field as union. v4(Jani Nikula): - The kernel-doc comment should be "/**" - Move all the rbtree macros to rbtree.h and add parens to ensure correct precedence. v5: - Remove the inline in a .c file (Jani Nikula). v6(Peter Zijlstra): - Add rb_add() function replacing the existing rbtree_insert() code. v7: - A full walk iteration in rbtree is slower than the list (Peter Zijlstra). - The existing rbtree_postorder_for_each_entry_safe macro should be used in scenarios where traversal order is not a critical factor (Christian). Cc: stable(a)vger.kernel.org Fixes: a68c7eaa7a8f ("drm/amdgpu: Enable clear page functionality") Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam(a)amd.com> --- drivers/gpu/drm/drm_buddy.c | 188 ++++++++++++++++++++++-------------- include/drm/drm_buddy.h | 11 ++- 2 files changed, 124 insertions(+), 75 deletions(-) diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c index a94061f373de..67aa67229cc3 100644 --- a/drivers/gpu/drm/drm_buddy.c +++ b/drivers/gpu/drm/drm_buddy.c @@ -14,6 +14,8 @@ static struct kmem_cache *slab_blocks; +#define rbtree_get_free_block(node) rb_entry((node), struct drm_buddy_block, rb) + static struct drm_buddy_block *drm_block_alloc(struct drm_buddy *mm, struct drm_buddy_block *parent, unsigned int order, @@ -31,6 +33,8 @@ static struct drm_buddy_block *drm_block_alloc(struct drm_buddy *mm, block->header |= order; block->parent = parent; + RB_CLEAR_NODE(&block->rb); + BUG_ON(block->header & DRM_BUDDY_HEADER_UNUSED); return block; } @@ -41,23 +45,49 @@ static void drm_block_free(struct drm_buddy *mm, kmem_cache_free(slab_blocks, block); } -static void list_insert_sorted(struct drm_buddy *mm, - struct drm_buddy_block *block) +static bool drm_buddy_block_offset_less(const struct drm_buddy_block *block, + const struct drm_buddy_block *node) { - struct drm_buddy_block *node; - struct list_head *head; + return drm_buddy_block_offset(block) < drm_buddy_block_offset(node); +} - head = &mm->free_list[drm_buddy_block_order(block)]; - if (list_empty(head)) { - list_add(&block->link, head); - return; - } +static bool rbtree_block_offset_less(struct rb_node *block, + const struct rb_node *node) +{ + return drm_buddy_block_offset_less(rbtree_get_free_block(block), + rbtree_get_free_block(node)); +} - list_for_each_entry(node, head, link) - if (drm_buddy_block_offset(block) < drm_buddy_block_offset(node)) - break; +static void rbtree_insert(struct drm_buddy *mm, + struct drm_buddy_block *block) +{ + rb_add(&block->rb, + &mm->free_tree[drm_buddy_block_order(block)], + rbtree_block_offset_less); +} + +static void rbtree_remove(struct drm_buddy *mm, + struct drm_buddy_block *block) +{ + struct rb_root *root; + + root = &mm->free_tree[drm_buddy_block_order(block)]; + rb_erase(&block->rb, root); - __list_add(&block->link, node->link.prev, &node->link); + RB_CLEAR_NODE(&block->rb); +} + +static struct drm_buddy_block * +rbtree_last_entry(struct drm_buddy *mm, unsigned int order) +{ + struct rb_node *node = rb_last(&mm->free_tree[order]); + + return node ? rb_entry(node, struct drm_buddy_block, rb) : NULL; +} + +static bool rbtree_is_empty(struct drm_buddy *mm, unsigned int order) +{ + return RB_EMPTY_ROOT(&mm->free_tree[order]); } static void clear_reset(struct drm_buddy_block *block) @@ -70,12 +100,13 @@ static void mark_cleared(struct drm_buddy_block *block) block->header |= DRM_BUDDY_HEADER_CLEAR; } -static void mark_allocated(struct drm_buddy_block *block) +static void mark_allocated(struct drm_buddy *mm, + struct drm_buddy_block *block) { block->header &= ~DRM_BUDDY_HEADER_STATE; block->header |= DRM_BUDDY_ALLOCATED; - list_del(&block->link); + rbtree_remove(mm, block); } static void mark_free(struct drm_buddy *mm, @@ -84,15 +115,16 @@ static void mark_free(struct drm_buddy *mm, block->header &= ~DRM_BUDDY_HEADER_STATE; block->header |= DRM_BUDDY_FREE; - list_insert_sorted(mm, block); + rbtree_insert(mm, block); } -static void mark_split(struct drm_buddy_block *block) +static void mark_split(struct drm_buddy *mm, + struct drm_buddy_block *block) { block->header &= ~DRM_BUDDY_HEADER_STATE; block->header |= DRM_BUDDY_SPLIT; - list_del(&block->link); + rbtree_remove(mm, block); } static inline bool overlaps(u64 s1, u64 e1, u64 s2, u64 e2) @@ -148,7 +180,7 @@ static unsigned int __drm_buddy_free(struct drm_buddy *mm, mark_cleared(parent); } - list_del(&buddy->link); + rbtree_remove(mm, buddy); if (force_merge && drm_buddy_block_is_clear(buddy)) mm->clear_avail -= drm_buddy_block_size(mm, buddy); @@ -179,13 +211,19 @@ static int __force_merge(struct drm_buddy *mm, return -EINVAL; for (i = min_order - 1; i >= 0; i--) { - struct drm_buddy_block *block, *prev; + struct rb_root *root = &mm->free_tree[i]; + struct rb_node *iter; + + iter = rb_last(root); - list_for_each_entry_safe_reverse(block, prev, &mm->free_list[i], link) { - struct drm_buddy_block *buddy; + while (iter) { + struct drm_buddy_block *block, *buddy; u64 block_start, block_end; - if (!block->parent) + block = rbtree_get_free_block(iter); + iter = rb_prev(iter); + + if (!block || !block->parent) continue; block_start = drm_buddy_block_offset(block); @@ -201,15 +239,10 @@ static int __force_merge(struct drm_buddy *mm, WARN_ON(drm_buddy_block_is_clear(block) == drm_buddy_block_is_clear(buddy)); - /* - * If the prev block is same as buddy, don't access the - * block in the next iteration as we would free the - * buddy block as part of the free function. - */ - if (prev == buddy) - prev = list_prev_entry(prev, link); + if (iter == &buddy->rb) + iter = rb_prev(iter); - list_del(&block->link); + rbtree_remove(mm, block); if (drm_buddy_block_is_clear(block)) mm->clear_avail -= drm_buddy_block_size(mm, block); @@ -258,14 +291,14 @@ int drm_buddy_init(struct drm_buddy *mm, u64 size, u64 chunk_size) BUG_ON(mm->max_order > DRM_BUDDY_MAX_ORDER); - mm->free_list = kmalloc_array(mm->max_order + 1, - sizeof(struct list_head), + mm->free_tree = kmalloc_array(mm->max_order + 1, + sizeof(struct rb_root), GFP_KERNEL); - if (!mm->free_list) + if (!mm->free_tree) return -ENOMEM; for (i = 0; i <= mm->max_order; ++i) - INIT_LIST_HEAD(&mm->free_list[i]); + mm->free_tree[i] = RB_ROOT; mm->n_roots = hweight64(size); @@ -273,7 +306,7 @@ int drm_buddy_init(struct drm_buddy *mm, u64 size, u64 chunk_size) sizeof(struct drm_buddy_block *), GFP_KERNEL); if (!mm->roots) - goto out_free_list; + goto out_free_tree; offset = 0; i = 0; @@ -312,8 +345,8 @@ int drm_buddy_init(struct drm_buddy *mm, u64 size, u64 chunk_size) while (i--) drm_block_free(mm, mm->roots[i]); kfree(mm->roots); -out_free_list: - kfree(mm->free_list); +out_free_tree: + kfree(mm->free_tree); return -ENOMEM; } EXPORT_SYMBOL(drm_buddy_init); @@ -323,7 +356,7 @@ EXPORT_SYMBOL(drm_buddy_init); * * @mm: DRM buddy manager to free * - * Cleanup memory manager resources and the freelist + * Cleanup memory manager resources and the freetree */ void drm_buddy_fini(struct drm_buddy *mm) { @@ -350,7 +383,7 @@ void drm_buddy_fini(struct drm_buddy *mm) WARN_ON(mm->avail != mm->size); kfree(mm->roots); - kfree(mm->free_list); + kfree(mm->free_tree); } EXPORT_SYMBOL(drm_buddy_fini); @@ -383,7 +416,7 @@ static int split_block(struct drm_buddy *mm, clear_reset(block); } - mark_split(block); + mark_split(mm, block); return 0; } @@ -412,7 +445,7 @@ EXPORT_SYMBOL(drm_get_buddy); * @is_clear: blocks clear state * * Reset the clear state based on @is_clear value for each block - * in the freelist. + * in the freetree. */ void drm_buddy_reset_clear(struct drm_buddy *mm, bool is_clear) { @@ -431,9 +464,9 @@ void drm_buddy_reset_clear(struct drm_buddy *mm, bool is_clear) } for (i = 0; i <= mm->max_order; ++i) { - struct drm_buddy_block *block; + struct drm_buddy_block *block, *tmp; - list_for_each_entry_reverse(block, &mm->free_list[i], link) { + rbtree_postorder_for_each_entry_safe(block, tmp, &mm->free_tree[i], rb) { if (is_clear != drm_buddy_block_is_clear(block)) { if (is_clear) { mark_cleared(block); @@ -639,14 +672,18 @@ get_maxblock(struct drm_buddy *mm, unsigned int order, unsigned int i; for (i = order; i <= mm->max_order; ++i) { + struct rb_node *iter = rb_last(&mm->free_tree[i]); struct drm_buddy_block *tmp_block; - list_for_each_entry_reverse(tmp_block, &mm->free_list[i], link) { - if (block_incompatible(tmp_block, flags)) - continue; + while (iter) { + tmp_block = rbtree_get_free_block(iter); - block = tmp_block; - break; + if (!block_incompatible(tmp_block, flags)) { + block = tmp_block; + break; + } + + iter = rb_prev(iter); } if (!block) @@ -667,7 +704,7 @@ get_maxblock(struct drm_buddy *mm, unsigned int order, } static struct drm_buddy_block * -alloc_from_freelist(struct drm_buddy *mm, +alloc_from_freetree(struct drm_buddy *mm, unsigned int order, unsigned long flags) { @@ -682,14 +719,18 @@ alloc_from_freelist(struct drm_buddy *mm, tmp = drm_buddy_block_order(block); } else { for (tmp = order; tmp <= mm->max_order; ++tmp) { + struct rb_node *iter = rb_last(&mm->free_tree[tmp]); struct drm_buddy_block *tmp_block; - list_for_each_entry_reverse(tmp_block, &mm->free_list[tmp], link) { - if (block_incompatible(tmp_block, flags)) - continue; + while (iter) { + tmp_block = rbtree_get_free_block(iter); - block = tmp_block; - break; + if (!block_incompatible(tmp_block, flags)) { + block = tmp_block; + break; + } + + iter = rb_prev(iter); } if (block) @@ -700,10 +741,8 @@ alloc_from_freelist(struct drm_buddy *mm, if (!block) { /* Fallback method */ for (tmp = order; tmp <= mm->max_order; ++tmp) { - if (!list_empty(&mm->free_list[tmp])) { - block = list_last_entry(&mm->free_list[tmp], - struct drm_buddy_block, - link); + if (!rbtree_is_empty(mm, tmp)) { + block = rbtree_last_entry(mm, tmp); if (block) break; } @@ -771,7 +810,7 @@ static int __alloc_range(struct drm_buddy *mm, if (contains(start, end, block_start, block_end)) { if (drm_buddy_block_is_free(block)) { - mark_allocated(block); + mark_allocated(mm, block); total_allocated += drm_buddy_block_size(mm, block); mm->avail -= drm_buddy_block_size(mm, block); if (drm_buddy_block_is_clear(block)) @@ -849,8 +888,8 @@ static int __alloc_contig_try_harder(struct drm_buddy *mm, { u64 rhs_offset, lhs_offset, lhs_size, filled; struct drm_buddy_block *block; - struct list_head *list; LIST_HEAD(blocks_lhs); + struct rb_node *iter; unsigned long pages; unsigned int order; u64 modify_size; @@ -862,11 +901,14 @@ static int __alloc_contig_try_harder(struct drm_buddy *mm, if (order == 0) return -ENOSPC; - list = &mm->free_list[order]; - if (list_empty(list)) + if (rbtree_is_empty(mm, order)) return -ENOSPC; - list_for_each_entry_reverse(block, list, link) { + iter = rb_last(&mm->free_tree[order]); + + while (iter) { + block = rbtree_get_free_block(iter); + /* Allocate blocks traversing RHS */ rhs_offset = drm_buddy_block_offset(block); err = __drm_buddy_alloc_range(mm, rhs_offset, size, @@ -891,6 +933,8 @@ static int __alloc_contig_try_harder(struct drm_buddy *mm, } /* Free blocks for the next iteration */ drm_buddy_free_list_internal(mm, blocks); + + iter = rb_prev(iter); } return -ENOSPC; @@ -976,7 +1020,7 @@ int drm_buddy_block_trim(struct drm_buddy *mm, list_add(&block->tmp_link, &dfs); err = __alloc_range(mm, &dfs, new_start, new_size, blocks, NULL); if (err) { - mark_allocated(block); + mark_allocated(mm, block); mm->avail -= drm_buddy_block_size(mm, block); if (drm_buddy_block_is_clear(block)) mm->clear_avail -= drm_buddy_block_size(mm, block); @@ -999,8 +1043,8 @@ __drm_buddy_alloc_blocks(struct drm_buddy *mm, return __drm_buddy_alloc_range_bias(mm, start, end, order, flags); else - /* Allocate from freelist */ - return alloc_from_freelist(mm, order, flags); + /* Allocate from freetree */ + return alloc_from_freetree(mm, order, flags); } /** @@ -1017,8 +1061,8 @@ __drm_buddy_alloc_blocks(struct drm_buddy *mm, * alloc_range_bias() called on range limitations, which traverses * the tree and returns the desired block. * - * alloc_from_freelist() called when *no* range restrictions - * are enforced, which picks the block from the freelist. + * alloc_from_freetree() called when *no* range restrictions + * are enforced, which picks the block from the freetree. * * Returns: * 0 on success, error code on failure. @@ -1120,7 +1164,7 @@ int drm_buddy_alloc_blocks(struct drm_buddy *mm, } } while (1); - mark_allocated(block); + mark_allocated(mm, block); mm->avail -= drm_buddy_block_size(mm, block); if (drm_buddy_block_is_clear(block)) mm->clear_avail -= drm_buddy_block_size(mm, block); @@ -1201,10 +1245,10 @@ void drm_buddy_print(struct drm_buddy *mm, struct drm_printer *p) mm->chunk_size >> 10, mm->size >> 20, mm->avail >> 20, mm->clear_avail >> 20); for (order = mm->max_order; order >= 0; order--) { - struct drm_buddy_block *block; + struct drm_buddy_block *block, *tmp; u64 count = 0, free; - list_for_each_entry(block, &mm->free_list[order], link) { + rbtree_postorder_for_each_entry_safe(block, tmp, &mm->free_tree[order], rb) { BUG_ON(!drm_buddy_block_is_free(block)); count++; } diff --git a/include/drm/drm_buddy.h b/include/drm/drm_buddy.h index 513837632b7d..9ee105d4309f 100644 --- a/include/drm/drm_buddy.h +++ b/include/drm/drm_buddy.h @@ -10,6 +10,7 @@ #include <linux/list.h> #include <linux/slab.h> #include <linux/sched.h> +#include <linux/rbtree.h> #include <drm/drm_print.h> @@ -53,7 +54,11 @@ struct drm_buddy_block { * a list, if so desired. As soon as the block is freed with * drm_buddy_free* ownership is given back to the mm. */ - struct list_head link; + union { + struct rb_node rb; + struct list_head link; + }; + struct list_head tmp_link; }; @@ -68,7 +73,7 @@ struct drm_buddy_block { */ struct drm_buddy { /* Maintain a free list for each order. */ - struct list_head *free_list; + struct rb_root *free_tree; /* * Maintain explicit binary tree(s) to track the allocation of the @@ -94,7 +99,7 @@ struct drm_buddy { }; static inline u64 -drm_buddy_block_offset(struct drm_buddy_block *block) +drm_buddy_block_offset(const struct drm_buddy_block *block) { return block->header & DRM_BUDDY_HEADER_OFFSET; } base-commit: 3a9cf301794c1a49d95eeb13119ff490fb5cfe88 -- 2.34.1

1 month, 1 week

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Re: [PATCH v2] comedi: fix divide-by-zero in comedi_buf_munge()

by Deepanshu Kartikey

Hello Ian and maintainers, Just a gentle ping on this patch. It's been 10 days since v2 was sent incorporating Ian's feedback to merge the chanlist_len check with the existing early return. Please let me know if any further changes are needed. Thank you, Deepanshu

1 month, 1 week

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FAILED: patch "[PATCH] media: tuner: xc5000: Fix use-after-free in xc5000_release

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 40b7a19f321e65789612ebaca966472055dab48c # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025100341-dime-left-e15f@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 40b7a19f321e65789612ebaca966472055dab48c Mon Sep 17 00:00:00 2001 From: Duoming Zhou <duoming(a)zju.edu.cn> Date: Wed, 17 Sep 2025 17:56:08 +0800 Subject: [PATCH] media: tuner: xc5000: Fix use-after-free in xc5000_release The original code uses cancel_delayed_work() in xc5000_release(), which does not guarantee that the delayed work item timer_sleep has fully completed if it was already running. This leads to use-after-free scenarios where xc5000_release() may free the xc5000_priv while timer_sleep is still active and attempts to dereference the xc5000_priv. A typical race condition is illustrated below: CPU 0 (release thread) | CPU 1 (delayed work callback) xc5000_release() | xc5000_do_timer_sleep() cancel_delayed_work() | hybrid_tuner_release_state(priv) | kfree(priv) | | priv = container_of() // UAF Replace cancel_delayed_work() with cancel_delayed_work_sync() to ensure that the timer_sleep is properly canceled before the xc5000_priv memory is deallocated. A deadlock concern was considered: xc5000_release() is called in a process context and is not holding any locks that the timer_sleep work item might also need. Therefore, the use of the _sync() variant is safe here. This bug was initially identified through static analysis. Fixes: f7a27ff1fb77 ("[media] xc5000: delay tuner sleep to 5 seconds") Cc: stable(a)vger.kernel.org Signed-off-by: Duoming Zhou <duoming(a)zju.edu.cn> Signed-off-by: Hans Verkuil <hverkuil+cisco(a)kernel.org> [hverkuil: fix typo in Subject: tunner -> tuner] diff --git a/drivers/media/tuners/xc5000.c b/drivers/media/tuners/xc5000.c index bf4ff461e082..a28481edd22e 100644 --- a/drivers/media/tuners/xc5000.c +++ b/drivers/media/tuners/xc5000.c @@ -1304,7 +1304,7 @@ static void xc5000_release(struct dvb_frontend *fe) mutex_lock(&xc5000_list_mutex); if (priv) { - cancel_delayed_work(&priv->timer_sleep); + cancel_delayed_work_sync(&priv->timer_sleep); hybrid_tuner_release_state(priv); }

1 month, 1 week

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Please backport commit a40282dd3c48 ("gcc-plugins: Remove TODO_verify_il for GCC >= 16")

by Kees Cook

Hi, Please backport: commit a40282dd3c48 ("gcc-plugins: Remove TODO_verify_il for GCC >= 16") to all stable kernel versions. This prepares the GCC plugins for the coming GCC 16 release. Thanks! -Kees -- Kees Cook

1 month, 1 week

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FAILED: patch "[PATCH] media: tuner: xc5000: Fix use-after-free in xc5000_release

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 40b7a19f321e65789612ebaca966472055dab48c # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025100341-cobbler-alabaster-748a@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 40b7a19f321e65789612ebaca966472055dab48c Mon Sep 17 00:00:00 2001 From: Duoming Zhou <duoming(a)zju.edu.cn> Date: Wed, 17 Sep 2025 17:56:08 +0800 Subject: [PATCH] media: tuner: xc5000: Fix use-after-free in xc5000_release The original code uses cancel_delayed_work() in xc5000_release(), which does not guarantee that the delayed work item timer_sleep has fully completed if it was already running. This leads to use-after-free scenarios where xc5000_release() may free the xc5000_priv while timer_sleep is still active and attempts to dereference the xc5000_priv. A typical race condition is illustrated below: CPU 0 (release thread) | CPU 1 (delayed work callback) xc5000_release() | xc5000_do_timer_sleep() cancel_delayed_work() | hybrid_tuner_release_state(priv) | kfree(priv) | | priv = container_of() // UAF Replace cancel_delayed_work() with cancel_delayed_work_sync() to ensure that the timer_sleep is properly canceled before the xc5000_priv memory is deallocated. A deadlock concern was considered: xc5000_release() is called in a process context and is not holding any locks that the timer_sleep work item might also need. Therefore, the use of the _sync() variant is safe here. This bug was initially identified through static analysis. Fixes: f7a27ff1fb77 ("[media] xc5000: delay tuner sleep to 5 seconds") Cc: stable(a)vger.kernel.org Signed-off-by: Duoming Zhou <duoming(a)zju.edu.cn> Signed-off-by: Hans Verkuil <hverkuil+cisco(a)kernel.org> [hverkuil: fix typo in Subject: tunner -> tuner] diff --git a/drivers/media/tuners/xc5000.c b/drivers/media/tuners/xc5000.c index bf4ff461e082..a28481edd22e 100644 --- a/drivers/media/tuners/xc5000.c +++ b/drivers/media/tuners/xc5000.c @@ -1304,7 +1304,7 @@ static void xc5000_release(struct dvb_frontend *fe) mutex_lock(&xc5000_list_mutex); if (priv) { - cancel_delayed_work(&priv->timer_sleep); + cancel_delayed_work_sync(&priv->timer_sleep); hybrid_tuner_release_state(priv); }

1 month, 1 week

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Investitionsprojekt

by Hallo

Guten Morgen, mein Name ist Shun Tung, und ich vertrete die Interessen der Familie Wing Mau, die an verschiedenen Investitionsmöglichkeiten in Ihrem Land interessiert ist. Besonders interessieren wir uns für die Sektoren Immobilien, Tourismus, erneuerbare Energien und Fertigung. Aufgrund politischer Herausforderungen in unserem Heimatland suchen wir einen zuverlässigen und vertrauenswürdigen Partner im Ausland, der diese Investitionen in unserem Auftrag verwaltet und absichert. Ihre Rolle würde darin bestehen, die Investitionen zu überwachen und sicherzustellen, dass sie erfolgreich sind. Im Gegenzug würden Sie einen vereinbarten Prozentsatz der Managementgebühren erhalten, während die Gewinne gleichmäßig zwischen beiden Parteien aufgeteilt werden. Falls dieses Angebot Ihr Interesse weckt, würde ich mich über ein weiteres Gespräch freuen. Ich freue mich auf Ihre Antwort. Mit freundlichen Grüßen, Shun Tung

1 month, 1 week

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[PATCH Linux-5.15.y Linux-5.10.y Linux-5.4.y 1/1] udp: Fix memory accounting leak.

by Yifei Liu

From: Kuniyuki Iwashima <kuniyu(a)amazon.com> [ Upstream commit df207de9d9e7a4d92f8567e2c539d9c8c12fd99d ] Matt Dowling reported a weird UDP memory usage issue. Under normal operation, the UDP memory usage reported in /proc/net/sockstat remains close to zero. However, it occasionally spiked to 524,288 pages and never dropped. Moreover, the value doubled when the application was terminated. Finally, it caused intermittent packet drops. We can reproduce the issue with the script below [0]: 1. /proc/net/sockstat reports 0 pages # cat /proc/net/sockstat | grep UDP: UDP: inuse 1 mem 0 2. Run the script till the report reaches 524,288 # python3 test.py & sleep 5 # cat /proc/net/sockstat | grep UDP: UDP: inuse 3 mem 524288 <-- (INT_MAX + 1) >> PAGE_SHIFT 3. Kill the socket and confirm the number never drops # pkill python3 && sleep 5 # cat /proc/net/sockstat | grep UDP: UDP: inuse 1 mem 524288 4. (necessary since v6.0) Trigger proto_memory_pcpu_drain() # python3 test.py & sleep 1 && pkill python3 5. The number doubles # cat /proc/net/sockstat | grep UDP: UDP: inuse 1 mem 1048577 The application set INT_MAX to SO_RCVBUF, which triggered an integer overflow in udp_rmem_release(). When a socket is close()d, udp_destruct_common() purges its receive queue and sums up skb->truesize in the queue. This total is calculated and stored in a local unsigned integer variable. The total size is then passed to udp_rmem_release() to adjust memory accounting. However, because the function takes a signed integer argument, the total size can wrap around, causing an overflow. Then, the released amount is calculated as follows: 1) Add size to sk->sk_forward_alloc. 2) Round down sk->sk_forward_alloc to the nearest lower multiple of PAGE_SIZE and assign it to amount. 3) Subtract amount from sk->sk_forward_alloc. 4) Pass amount >> PAGE_SHIFT to __sk_mem_reduce_allocated(). When the issue occurred, the total in udp_destruct_common() was 2147484480 (INT_MAX + 833), which was cast to -2147482816 in udp_rmem_release(). At 1) sk->sk_forward_alloc is changed from 3264 to -2147479552, and 2) sets -2147479552 to amount. 3) reverts the wraparound, so we don't see a warning in inet_sock_destruct(). However, udp_memory_allocated ends up doubling at 4). Since commit 3cd3399dd7a8 ("net: implement per-cpu reserves for memory_allocated"), memory usage no longer doubles immediately after a socket is close()d because __sk_mem_reduce_allocated() caches the amount in udp_memory_per_cpu_fw_alloc. However, the next time a UDP socket receives a packet, the subtraction takes effect, causing UDP memory usage to double. This issue makes further memory allocation fail once the socket's sk->sk_rmem_alloc exceeds net.ipv4.udp_rmem_min, resulting in packet drops. To prevent this issue, let's use unsigned int for the calculation and call sk_forward_alloc_add() only once for the small delta. Note that first_packet_length() also potentially has the same problem. [0]: from socket import * SO_RCVBUFFORCE = 33 INT_MAX = (2 ** 31) - 1 s = socket(AF_INET, SOCK_DGRAM) s.bind(('', 0)) s.setsockopt(SOL_SOCKET, SO_RCVBUFFORCE, INT_MAX) c = socket(AF_INET, SOCK_DGRAM) c.connect(s.getsockname()) data = b'a' * 100 while True: c.send(data) Fixes: f970bd9e3a06 ("udp: implement memory accounting helpers") Reported-by: Matt Dowling <madowlin(a)amazon.com> Signed-off-by: Kuniyuki Iwashima <kuniyu(a)amazon.com> Reviewed-by: Willem de Bruijn <willemb(a)google.com> Link: https://patch.msgid.link/20250401184501.67377-3-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba(a)kernel.org> (cherry picked from commit df207de9d9e7a4d92f8567e2c539d9c8c12fd99d) [Yifei: resolve minor conflicts and fix CVE-2025-22058] Signed-off-by: Yifei Liu <yifei.l.liu(a)oracle.com> --- net/ipv4/udp.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 51a12fa486b6..3ebd5765fb9f 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1459,12 +1459,12 @@ static bool udp_skb_has_head_state(struct sk_buff *skb) } /* fully reclaim rmem/fwd memory allocated for skb */ -static void udp_rmem_release(struct sock *sk, int size, int partial, - bool rx_queue_lock_held) +static void udp_rmem_release(struct sock *sk, unsigned int size, + int partial, bool rx_queue_lock_held) { struct udp_sock *up = udp_sk(sk); struct sk_buff_head *sk_queue; - int amt; + unsigned int amt; if (likely(partial)) { up->forward_deficit += size; @@ -1484,10 +1484,8 @@ static void udp_rmem_release(struct sock *sk, int size, int partial, if (!rx_queue_lock_held) spin_lock(&sk_queue->lock); - - sk->sk_forward_alloc += size; - amt = (sk->sk_forward_alloc - partial) & ~(SK_MEM_QUANTUM - 1); - sk->sk_forward_alloc -= amt; + amt = (size + sk->sk_forward_alloc - partial) & ~(PAGE_SIZE - 1); + sk->sk_forward_alloc += size - amt; if (amt) __sk_mem_reduce_allocated(sk, amt >> SK_MEM_QUANTUM_SHIFT); @@ -1671,7 +1669,7 @@ EXPORT_SYMBOL_GPL(skb_consume_udp); static struct sk_buff *__first_packet_length(struct sock *sk, struct sk_buff_head *rcvq, - int *total) + unsigned int *total) { struct sk_buff *skb; @@ -1704,8 +1702,8 @@ static int first_packet_length(struct sock *sk) { struct sk_buff_head *rcvq = &udp_sk(sk)->reader_queue; struct sk_buff_head *sk_queue = &sk->sk_receive_queue; + unsigned int total = 0; struct sk_buff *skb; - int total = 0; int res; spin_lock_bh(&rcvq->lock); -- 2.50.1

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[PATCH v1] rust: cfi: only 64-bit arm and x86 support CFI_CLANG

by Conor Dooley

From: Conor Dooley <conor.dooley(a)microchip.com> The kernel uses the standard rustc targets for non-x86 targets, and out of those only 64-bit arm's target has kcfi support enabled. For x86, the custom 64-bit target enables kcfi. The HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC config option that allows CFI_CLANG to be used in combination with RUST does not check whether the rustc target supports kcfi. This breaks the build on riscv (and presumably 32-bit arm) when CFI_CLANG and RUST are enabled at the same time. Ordinarily, a rustc-option check would be used to detect target support but unfortunately rustc-option filters out the target for reasons given in commit 46e24a545cdb4 ("rust: kasan/kbuild: fix missing flags on first build"). As a result, if the host supports kcfi but the target does not, e.g. when building for riscv on x86_64, the build would remain broken. Instead, make HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC depend on the only two architectures where the target used supports it to fix the build. CC: stable(a)vger.kernel.org Fixes: ca627e636551e ("rust: cfi: add support for CFI_CLANG with Rust") Signed-off-by: Conor Dooley <conor.dooley(a)microchip.com> --- CC: Paul Walmsley <paul.walmsley(a)sifive.com> CC: Palmer Dabbelt <palmer(a)dabbelt.com> CC: Alexandre Ghiti <alex(a)ghiti.fr> CC: Miguel Ojeda <ojeda(a)kernel.org> CC: Alex Gaynor <alex.gaynor(a)gmail.com> CC: Boqun Feng <boqun.feng(a)gmail.com> CC: Gary Guo <gary(a)garyguo.net> CC: "Björn Roy Baron" <bjorn3_gh(a)protonmail.com> CC: Benno Lossin <lossin(a)kernel.org> CC: Andreas Hindborg <a.hindborg(a)kernel.org> CC: Alice Ryhl <aliceryhl(a)google.com> CC: Trevor Gross <tmgross(a)umich.edu> CC: Danilo Krummrich <dakr(a)kernel.org> CC: Kees Cook <kees(a)kernel.org> CC: Sami Tolvanen <samitolvanen(a)google.com> CC: Matthew Maurer <mmaurer(a)google.com> CC: "Peter Zijlstra (Intel)" <peterz(a)infradead.org> CC: linux-kernel(a)vger.kernel.org CC: linux-riscv(a)lists.infradead.org CC: rust-for-linux(a)vger.kernel.org --- arch/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/Kconfig b/arch/Kconfig index d1b4ffd6e0856..880cddff5eda7 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -917,6 +917,7 @@ config HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC def_bool y depends on HAVE_CFI_ICALL_NORMALIZE_INTEGERS_CLANG depends on RUSTC_VERSION >= 107900 + depends on ARM64 || X86_64 # With GCOV/KASAN we need this fix: https://github.com/rust-lang/rust/pull/129373 depends on (RUSTC_LLVM_VERSION >= 190103 && RUSTC_VERSION >= 108200) || \ (!GCOV_KERNEL && !KASAN_GENERIC && !KASAN_SW_TAGS) -- 2.47.2

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FAILED: patch "[PATCH] media: rc: fix races with imon_disconnect()" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x fa0f61cc1d828178aa921475a9b786e7fbb65ccb # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025100320-pout-unwired-1096@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From fa0f61cc1d828178aa921475a9b786e7fbb65ccb Mon Sep 17 00:00:00 2001 From: Larshin Sergey <Sergey.Larshin(a)kaspersky.com> Date: Tue, 29 Jul 2025 13:13:32 +0300 Subject: [PATCH] media: rc: fix races with imon_disconnect() Syzbot reports a KASAN issue as below: BUG: KASAN: use-after-free in __create_pipe include/linux/usb.h:1945 [inline] BUG: KASAN: use-after-free in send_packet+0xa2d/0xbc0 drivers/media/rc/imon.c:627 Read of size 4 at addr ffff8880256fb000 by task syz-executor314/4465 CPU: 2 PID: 4465 Comm: syz-executor314 Not tainted 6.0.0-rc1-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:317 [inline] print_report.cold+0x2ba/0x6e9 mm/kasan/report.c:433 kasan_report+0xb1/0x1e0 mm/kasan/report.c:495 __create_pipe include/linux/usb.h:1945 [inline] send_packet+0xa2d/0xbc0 drivers/media/rc/imon.c:627 vfd_write+0x2d9/0x550 drivers/media/rc/imon.c:991 vfs_write+0x2d7/0xdd0 fs/read_write.c:576 ksys_write+0x127/0x250 fs/read_write.c:631 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd The iMON driver improperly releases the usb_device reference in imon_disconnect without coordinating with active users of the device. Specifically, the fields usbdev_intf0 and usbdev_intf1 are not protected by the users counter (ictx->users). During probe, imon_init_intf0 or imon_init_intf1 increments the usb_device reference count depending on the interface. However, during disconnect, usb_put_dev is called unconditionally, regardless of actual usage. As a result, if vfd_write or other operations are still in progress after disconnect, this can lead to a use-after-free of the usb_device pointer. Thread 1 vfd_write Thread 2 imon_disconnect ... if usb_put_dev(ictx->usbdev_intf0) else usb_put_dev(ictx->usbdev_intf1) ... while send_packet if pipe = usb_sndintpipe( ictx->usbdev_intf0) UAF else pipe = usb_sndctrlpipe( ictx->usbdev_intf0, 0) UAF Guard access to usbdev_intf0 and usbdev_intf1 after disconnect by checking ictx->disconnected in all writer paths. Add early return with -ENODEV in send_packet(), vfd_write(), lcd_write() and display_open() if the device is no longer present. Set and read ictx->disconnected under ictx->lock to ensure memory synchronization. Acquire the lock in imon_disconnect() before setting the flag to synchronize with any ongoing operations. Ensure writers exit early and safely after disconnect before the USB core proceeds with cleanup. Found by Linux Verification Center (linuxtesting.org) with Syzkaller. Reported-by: syzbot+f1a69784f6efe748c3bf(a)syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=f1a69784f6efe748c3bf Fixes: 21677cfc562a ("V4L/DVB: ir-core: add imon driver") Cc: stable(a)vger.kernel.org Signed-off-by: Larshin Sergey <Sergey.Larshin(a)kaspersky.com> Signed-off-by: Sean Young <sean(a)mess.org> Signed-off-by: Hans Verkuil <hverkuil+cisco(a)kernel.org> diff --git a/drivers/media/rc/imon.c b/drivers/media/rc/imon.c index 91d05aadced3..35b9e07003d8 100644 --- a/drivers/media/rc/imon.c +++ b/drivers/media/rc/imon.c @@ -531,7 +531,9 @@ static int display_open(struct inode *inode, struct file *file) mutex_lock(&ictx->lock); - if (!ictx->display_supported) { + if (ictx->disconnected) { + retval = -ENODEV; + } else if (!ictx->display_supported) { pr_err("display not supported by device\n"); retval = -ENODEV; } else if (ictx->display_isopen) { @@ -595,6 +597,9 @@ static int send_packet(struct imon_context *ictx) lockdep_assert_held(&ictx->lock); + if (ictx->disconnected) + return -ENODEV; + /* Check if we need to use control or interrupt urb */ if (!ictx->tx_control) { pipe = usb_sndintpipe(ictx->usbdev_intf0, @@ -949,12 +954,14 @@ static ssize_t vfd_write(struct file *file, const char __user *buf, static const unsigned char vfd_packet6[] = { 0x01, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF }; - if (ictx->disconnected) - return -ENODEV; - if (mutex_lock_interruptible(&ictx->lock)) return -ERESTARTSYS; + if (ictx->disconnected) { + retval = -ENODEV; + goto exit; + } + if (!ictx->dev_present_intf0) { pr_err_ratelimited("no iMON device present\n"); retval = -ENODEV; @@ -1029,11 +1036,13 @@ static ssize_t lcd_write(struct file *file, const char __user *buf, int retval = 0; struct imon_context *ictx = file->private_data; - if (ictx->disconnected) - return -ENODEV; - mutex_lock(&ictx->lock); + if (ictx->disconnected) { + retval = -ENODEV; + goto exit; + } + if (!ictx->display_supported) { pr_err_ratelimited("no iMON display present\n"); retval = -ENODEV; @@ -2507,7 +2516,11 @@ static void imon_disconnect(struct usb_interface *interface) int ifnum; ictx = usb_get_intfdata(interface); + + mutex_lock(&ictx->lock); ictx->disconnected = true; + mutex_unlock(&ictx->lock); + dev = ictx->dev; ifnum = interface->cur_altsetting->desc.bInterfaceNumber;

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FAILED: patch "[PATCH] media: tuner: xc5000: Fix use-after-free in xc5000_release

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 40b7a19f321e65789612ebaca966472055dab48c # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025100340-pleat-amusable-e5dc@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 40b7a19f321e65789612ebaca966472055dab48c Mon Sep 17 00:00:00 2001 From: Duoming Zhou <duoming(a)zju.edu.cn> Date: Wed, 17 Sep 2025 17:56:08 +0800 Subject: [PATCH] media: tuner: xc5000: Fix use-after-free in xc5000_release The original code uses cancel_delayed_work() in xc5000_release(), which does not guarantee that the delayed work item timer_sleep has fully completed if it was already running. This leads to use-after-free scenarios where xc5000_release() may free the xc5000_priv while timer_sleep is still active and attempts to dereference the xc5000_priv. A typical race condition is illustrated below: CPU 0 (release thread) | CPU 1 (delayed work callback) xc5000_release() | xc5000_do_timer_sleep() cancel_delayed_work() | hybrid_tuner_release_state(priv) | kfree(priv) | | priv = container_of() // UAF Replace cancel_delayed_work() with cancel_delayed_work_sync() to ensure that the timer_sleep is properly canceled before the xc5000_priv memory is deallocated. A deadlock concern was considered: xc5000_release() is called in a process context and is not holding any locks that the timer_sleep work item might also need. Therefore, the use of the _sync() variant is safe here. This bug was initially identified through static analysis. Fixes: f7a27ff1fb77 ("[media] xc5000: delay tuner sleep to 5 seconds") Cc: stable(a)vger.kernel.org Signed-off-by: Duoming Zhou <duoming(a)zju.edu.cn> Signed-off-by: Hans Verkuil <hverkuil+cisco(a)kernel.org> [hverkuil: fix typo in Subject: tunner -> tuner] diff --git a/drivers/media/tuners/xc5000.c b/drivers/media/tuners/xc5000.c index bf4ff461e082..a28481edd22e 100644 --- a/drivers/media/tuners/xc5000.c +++ b/drivers/media/tuners/xc5000.c @@ -1304,7 +1304,7 @@ static void xc5000_release(struct dvb_frontend *fe) mutex_lock(&xc5000_list_mutex); if (priv) { - cancel_delayed_work(&priv->timer_sleep); + cancel_delayed_work_sync(&priv->timer_sleep); hybrid_tuner_release_state(priv); }

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