CVE-2025-38129

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> page_pool: Fix use-after-free in page_pool_recycle_in_ring<br /> <br /> syzbot reported a uaf in page_pool_recycle_in_ring:<br /> <br /> BUG: KASAN: slab-use-after-free in lock_release+0x151/0xa30 kernel/locking/lockdep.c:5862<br /> Read of size 8 at addr ffff8880286045a0 by task syz.0.284/6943<br /> <br /> CPU: 0 UID: 0 PID: 6943 Comm: syz.0.284 Not tainted 6.13.0-rc3-syzkaller-gdfa94ce54f41 #0<br /> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024<br /> Call Trace:<br /> <br /> __dump_stack lib/dump_stack.c:94 [inline]<br /> dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120<br /> print_address_description mm/kasan/report.c:378 [inline]<br /> print_report+0x169/0x550 mm/kasan/report.c:489<br /> kasan_report+0x143/0x180 mm/kasan/report.c:602<br /> lock_release+0x151/0xa30 kernel/locking/lockdep.c:5862<br /> __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:165 [inline]<br /> _raw_spin_unlock_bh+0x1b/0x40 kernel/locking/spinlock.c:210<br /> spin_unlock_bh include/linux/spinlock.h:396 [inline]<br /> ptr_ring_produce_bh include/linux/ptr_ring.h:164 [inline]<br /> page_pool_recycle_in_ring net/core/page_pool.c:707 [inline]<br /> page_pool_put_unrefed_netmem+0x748/0xb00 net/core/page_pool.c:826<br /> page_pool_put_netmem include/net/page_pool/helpers.h:323 [inline]<br /> page_pool_put_full_netmem include/net/page_pool/helpers.h:353 [inline]<br /> napi_pp_put_page+0x149/0x2b0 net/core/skbuff.c:1036<br /> skb_pp_recycle net/core/skbuff.c:1047 [inline]<br /> skb_free_head net/core/skbuff.c:1094 [inline]<br /> skb_release_data+0x6c4/0x8a0 net/core/skbuff.c:1125<br /> skb_release_all net/core/skbuff.c:1190 [inline]<br /> __kfree_skb net/core/skbuff.c:1204 [inline]<br /> sk_skb_reason_drop+0x1c9/0x380 net/core/skbuff.c:1242<br /> kfree_skb_reason include/linux/skbuff.h:1263 [inline]<br /> __skb_queue_purge_reason include/linux/skbuff.h:3343 [inline]<br /> <br /> root cause is:<br /> <br /> page_pool_recycle_in_ring<br /> ptr_ring_produce<br /> spin_lock(&amp;r-&gt;producer_lock);<br /> WRITE_ONCE(r-&gt;queue[r-&gt;producer++], ptr)<br /> //recycle last page to pool<br /> page_pool_release<br /> page_pool_scrub<br /> page_pool_empty_ring<br /> ptr_ring_consume<br /> page_pool_return_page //release all page<br /> __page_pool_destroy<br /> free_percpu(pool-&gt;recycle_stats);<br /> free(pool) //free<br /> <br /> spin_unlock(&amp;r-&gt;producer_lock); //pool-&gt;ring uaf read<br /> recycle_stat_inc(pool, ring);<br /> <br /> page_pool can be free while page pool recycle the last page in ring.<br /> Add producer-lock barrier to page_pool_release to prevent the page<br /> pool from being free before all pages have been recycled.<br /> <br /> recycle_stat_inc() is empty when CONFIG_PAGE_POOL_STATS is not<br /> enabled, which will trigger Wempty-body build warning. Add definition<br /> for pool stat macro to fix warning.