kernel/linux.git/net/core/page_pool.c, branch v6.1.168

page_pool: Fix use-after-free in page_pool_recycle_in_ring

2026-01-11T14:19:15+00:00

[ Upstream commit 271683bb2cf32e5126c592b5d5e6a756fa374fd9 ] syzbot reported a uaf in page_pool_recycle_in_ring: BUG: KASAN: slab-use-after-free in lock_release+0x151/0xa30 kernel/locking/lockdep.c:5862 Read of size 8 at addr ffff8880286045a0 by task syz.0.284/6943 CPU: 0 UID: 0 PID: 6943 Comm: syz.0.284 Not tainted 6.13.0-rc3-syzkaller-gdfa94ce54f41 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x169/0x550 mm/kasan/report.c:489 kasan_report+0x143/0x180 mm/kasan/report.c:602 lock_release+0x151/0xa30 kernel/locking/lockdep.c:5862 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:165 [inline] _raw_spin_unlock_bh+0x1b/0x40 kernel/locking/spinlock.c:210 spin_unlock_bh include/linux/spinlock.h:396 [inline] ptr_ring_produce_bh include/linux/ptr_ring.h:164 [inline] page_pool_recycle_in_ring net/core/page_pool.c:707 [inline] page_pool_put_unrefed_netmem+0x748/0xb00 net/core/page_pool.c:826 page_pool_put_netmem include/net/page_pool/helpers.h:323 [inline] page_pool_put_full_netmem include/net/page_pool/helpers.h:353 [inline] napi_pp_put_page+0x149/0x2b0 net/core/skbuff.c:1036 skb_pp_recycle net/core/skbuff.c:1047 [inline] skb_free_head net/core/skbuff.c:1094 [inline] skb_release_data+0x6c4/0x8a0 net/core/skbuff.c:1125 skb_release_all net/core/skbuff.c:1190 [inline] __kfree_skb net/core/skbuff.c:1204 [inline] sk_skb_reason_drop+0x1c9/0x380 net/core/skbuff.c:1242 kfree_skb_reason include/linux/skbuff.h:1263 [inline] __skb_queue_purge_reason include/linux/skbuff.h:3343 [inline] root cause is: page_pool_recycle_in_ring ptr_ring_produce spin_lock(&r->producer_lock); WRITE_ONCE(r->queue[r->producer++], ptr) //recycle last page to pool page_pool_release page_pool_scrub page_pool_empty_ring ptr_ring_consume page_pool_return_page //release all page __page_pool_destroy free_percpu(pool->recycle_stats); free(pool) //free spin_unlock(&r->producer_lock); //pool->ring uaf read recycle_stat_inc(pool, ring); page_pool can be free while page pool recycle the last page in ring. Add producer-lock barrier to page_pool_release to prevent the page pool from being free before all pages have been recycled. recycle_stat_inc() is empty when CONFIG_PAGE_POOL_STATS is not enabled, which will trigger Wempty-body build warning. Add definition for pool stat macro to fix warning. Suggested-by: Jakub Kicinski Link: https://lore.kernel.org/netdev/20250513083123.3514193-1-dongchenchen2@huawei.com Fixes: ff7d6b27f894 ("page_pool: refurbish version of page_pool code") Reported-by: syzbot+204a4382fcb3311f3858@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=204a4382fcb3311f3858 Signed-off-by: Dong Chenchen Reviewed-by: Toke Høiland-Jørgensen Reviewed-by: Mina Almasry Link: https://patch.msgid.link/20250527114152.3119109-1-dongchenchen2@huawei.com Signed-off-by: Jakub Kicinski [ Minor context change fixed. ] Signed-off-by: Ruohan Lan Signed-off-by: Greg Kroah-Hartman

page_pool: Clamp pool size to max 16K pages

2025-12-06T21:12:27+00:00

[ Upstream commit a1b501a8c6a87c9265fd03bd004035199e2e8128 ] page_pool_init() returns E2BIG when the page_pool size goes above 32K pages. As some drivers are configuring the page_pool size according to the MTU and ring size, there are cases where this limit is exceeded and the queue creation fails. The page_pool size doesn't have to cover a full queue, especially for larger ring size. So clamp the size instead of returning an error. Do this in the core to avoid having each driver do the clamping. The current limit was deemed to high [1] so it was reduced to 16K to avoid page waste. [1] https://lore.kernel.org/all/1758532715-820422-3-git-send-email-tariqt@nvidia.com/ Signed-off-by: Dragos Tatulea Reviewed-by: Tariq Toukan Link: https://patch.msgid.link/20250926131605.2276734-2-dtatulea@nvidia.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

page_pool: always add GFP_NOWARN for ATOMIC allocations

2025-12-06T21:12:24+00:00

[ Upstream commit f3b52167a0cb23b27414452fbc1278da2ee884fc ] Driver authors often forget to add GFP_NOWARN for page allocation from the datapath. This is annoying to users as OOMs are a fact of life, and we pretty much expect network Rx to hit page allocation failures during OOM. Make page pool add GFP_NOWARN for ATOMIC allocations by default. Reviewed-by: Mina Almasry Link: https://patch.msgid.link/20250912161703.361272-1-kuba@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

page_pool: avoid infinite loop to schedule delayed worker

2025-04-25T08:43:29+00:00

[ Upstream commit 43130d02baa137033c25297aaae95fd0edc41654 ] We noticed the kworker in page_pool_release_retry() was waken up repeatedly and infinitely in production because of the buggy driver causing the inflight less than 0 and warning us in page_pool_inflight()[1]. Since the inflight value goes negative, it means we should not expect the whole page_pool to get back to work normally. This patch mitigates the adverse effect by not rescheduling the kworker when detecting the inflight negative in page_pool_release_retry(). [1] [Mon Feb 10 20:36:11 2025] ------------[ cut here ]------------ [Mon Feb 10 20:36:11 2025] Negative(-51446) inflight packet-pages ... [Mon Feb 10 20:36:11 2025] Call Trace: [Mon Feb 10 20:36:11 2025] page_pool_release_retry+0x23/0x70 [Mon Feb 10 20:36:11 2025] process_one_work+0x1b1/0x370 [Mon Feb 10 20:36:11 2025] worker_thread+0x37/0x3a0 [Mon Feb 10 20:36:11 2025] kthread+0x11a/0x140 [Mon Feb 10 20:36:11 2025] ? process_one_work+0x370/0x370 [Mon Feb 10 20:36:11 2025] ? __kthread_cancel_work+0x40/0x40 [Mon Feb 10 20:36:11 2025] ret_from_fork+0x35/0x40 [Mon Feb 10 20:36:11 2025] ---[ end trace ebffe800f33e7e34 ]--- Note: before this patch, the above calltrace would flood the dmesg due to repeated reschedule of release_dw kworker. Signed-off-by: Jason Xing Reviewed-by: Mina Almasry Link: https://patch.msgid.link/20250214064250.85987-1-kerneljasonxing@gmail.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

net: page_pool: add missing free_percpu when page_pool_init fail

2023-11-20T10:52:16+00:00

[ Upstream commit 8ffbd1669ed1d58939d6e878dffaa2f60bf961a4 ] When ptr_ring_init() returns failure in page_pool_init(), free_percpu() is not called to free pool->recycle_stats, which may cause memory leak. Fixes: ad6fa1e1ab1b ("page_pool: Add recycle stats") Signed-off-by: Jian Shen Signed-off-by: Jijie Shao Reviewed-by: Yunsheng Lin Reviewed-by: Jiri Pirko Reviewed-by: Somnath Kotur Reviewed-by: Ilias Apalodimas Link: https://lore.kernel.org/r/20231030091256.2915394-1-shaojijie@huawei.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

page_pool: fix inconsistency for page_pool_ring_[un]lock()

2023-06-05T07:26:20+00:00

[ Upstream commit 368d3cb406cdd074d1df2ad9ec06d1bfcb664882 ] page_pool_ring_[un]lock() use in_softirq() to decide which spin lock variant to use, and when they are called in the context with in_softirq() being false, spin_lock_bh() is called in page_pool_ring_lock() while spin_unlock() is called in page_pool_ring_unlock(), because spin_lock_bh() has disabled the softirq in page_pool_ring_lock(), which causes inconsistency for spin lock pair calling. This patch fixes it by returning in_softirq state from page_pool_producer_lock(), and use it to decide which spin lock variant to use in page_pool_producer_unlock(). As pool->ring has both producer and consumer lock, so rename it to page_pool_producer_[un]lock() to reflect the actual usage. Also move them to page_pool.c as they are only used there, and remove the 'inline' as the compiler may have better idea to do inlining or not. Fixes: 7886244736a4 ("net: page_pool: Add bulk support for ptr_ring") Signed-off-by: Yunsheng Lin Acked-by: Jesper Dangaard Brouer Acked-by: Ilias Apalodimas Link: https://lore.kernel.org/r/20230522031714.5089-1-linyunsheng@huawei.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: page_pool: use in_softirq() instead

2023-06-05T07:26:20+00:00

[ Upstream commit 542bcea4be866b14b3a5c8e90773329066656c43 ] We use BH context only for synchronization, so we don't care if it's actually serving softirq or not. As a side node, in case of threaded NAPI, in_serving_softirq() will return false because it's in process context with BH off, making page_pool_recycle_in_cache() unreachable. Signed-off-by: Qingfang DENG Tested-by: Felix Fietkau Signed-off-by: David S. Miller Stable-dep-of: 368d3cb406cd ("page_pool: fix inconsistency for page_pool_ring_[un]lock()") Signed-off-by: Sasha Levin

Merge tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2022-08-05T23:32:45+00:00

Pull MM updates from Andrew Morton: "Most of the MM queue. A few things are still pending. Liam's maple tree rework didn't make it. This has resulted in a few other minor patch series being held over for next time. Multi-gen LRU still isn't merged as we were waiting for mapletree to stabilize. The current plan is to merge MGLRU into -mm soon and to later reintroduce mapletree, with a view to hopefully getting both into 6.1-rc1. Summary: - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe Lin, Yang Shi, Anshuman Khandual and Mike Rapoport - Some kmemleak fixes from Patrick Wang and Waiman Long - DAMON updates from SeongJae Park - memcg debug/visibility work from Roman Gushchin - vmalloc speedup from Uladzislau Rezki - more folio conversion work from Matthew Wilcox - enhancements for coherent device memory mapping from Alex Sierra - addition of shared pages tracking and CoW support for fsdax, from Shiyang Ruan - hugetlb optimizations from Mike Kravetz - Mel Gorman has contributed some pagealloc changes to improve latency and realtime behaviour. - mprotect soft-dirty checking has been improved by Peter Xu - Many other singleton patches all over the place" [ XFS merge from hell as per Darrick Wong in https://lore.kernel.org/all/YshKnxb4VwXycPO8@magnolia/ ] * tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (282 commits) tools/testing/selftests/vm/hmm-tests.c: fix build mm: Kconfig: fix typo mm: memory-failure: convert to pr_fmt() mm: use is_zone_movable_page() helper hugetlbfs: fix inaccurate comment in hugetlbfs_statfs() hugetlbfs: cleanup some comments in inode.c hugetlbfs: remove unneeded header file hugetlbfs: remove unneeded hugetlbfs_ops forward declaration hugetlbfs: use helper macro SZ_1{K,M} mm: cleanup is_highmem() mm/hmm: add a test for cross device private faults selftests: add soft-dirty into run_vmtests.sh selftests: soft-dirty: add test for mprotect mm/mprotect: fix soft-dirty check in can_change_pte_writable() mm: memcontrol: fix potential oom_lock recursion deadlock mm/gup.c: fix formatting in check_and_migrate_movable_page() xfs: fail dax mount if reflink is enabled on a partition mm/memcontrol.c: remove the redundant updating of stats_flush_threshold userfaultfd: don't fail on unrecognized features hugetlb_cgroup: fix wrong hugetlb cgroup numa stat ...

net: page_pool: optimize page pool page allocation in NUMA scenario

2022-07-08T00:03:16+00:00

Currently NIC packet receiving performance based on page pool deteriorates occasionally. To analysis the causes of this problem page allocation stats are collected. Here are the stats when NIC rx performance deteriorates: bandwidth(Gbits/s) 16.8 6.91 rx_pp_alloc_fast 13794308 21141869 rx_pp_alloc_slow 108625 166481 rx_pp_alloc_slow_h 0 0 rx_pp_alloc_empty 8192 8192 rx_pp_alloc_refill 0 0 rx_pp_alloc_waive 100433 158289 rx_pp_recycle_cached 0 0 rx_pp_recycle_cache_full 0 0 rx_pp_recycle_ring 362400 420281 rx_pp_recycle_ring_full 6064893 9709724 rx_pp_recycle_released_ref 0 0 The rx_pp_alloc_waive count indicates that a large number of pages' numa node are inconsistent with the NIC device numa node. Therefore these pages can't be reused by the page pool. As a result, many new pages would be allocated by __page_pool_alloc_pages_slow which is time consuming. This causes the NIC rx performance fluctuations. The main reason of huge numa mismatch pages in page pool is that page pool uses alloc_pages_bulk_array to allocate original pages. This function is not suitable for page allocation in NUMA scenario. So this patch uses alloc_pages_bulk_array_node which has a NUMA id input parameter to ensure the NUMA consistent between NIC device and allocated pages. Repeated NIC rx performance tests are performed 40 times. NIC rx bandwidth is higher and more stable compared to the datas above. Here are three test stats, the rx_pp_alloc_waive count is zero and rx_pp_alloc_slow which indicates pages allocated from slow patch is relatively low. bandwidth(Gbits/s) 93 93.9 93.8 rx_pp_alloc_fast 60066264 61266386 60938254 rx_pp_alloc_slow 16512 16517 16539 rx_pp_alloc_slow_ho 0 0 0 rx_pp_alloc_empty 16512 16517 16539 rx_pp_alloc_refill 473841 481910 481585 rx_pp_alloc_waive 0 0 0 rx_pp_recycle_cached 0 0 0 rx_pp_recycle_cache_full 0 0 0 rx_pp_recycle_ring 29754145 30358243 30194023 rx_pp_recycle_ring_full 0 0 0 rx_pp_recycle_released_ref 0 0 0 Signed-off-by: Jie Wang Acked-by: Jesper Dangaard Brouer Acked-by: Ilias Apalodimas Link: https://lore.kernel.org/r/20220705113515.54342-1-huangguangbin2@huawei.com Signed-off-by: Jakub Kicinski

mm/swap: convert __put_page() to __folio_put()

2022-07-04T01:08:47+00:00

Saves 11 bytes of text by removing a check of PageTail. Link: https://lkml.kernel.org/r/20220617175020.717127-16-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton