From a126061c80d5efb4baef4bcf346094139cd81df6 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 17 Dec 2024 13:51:21 +0000 Subject: [PATCH] ptr_ring: do not block hard interrupts in ptr_ring_resize_multiple() Jakub added a lockdep_assert_no_hardirq() check in __page_pool_put_page() to increase test coverage. syzbot found a splat caused by hard irq blocking in ptr_ring_resize_multiple() [1] As current users of ptr_ring_resize_multiple() do not require hard irqs being masked, replace it to only block BH. Rename helpers to better reflect they are safe against BH only. - ptr_ring_resize_multiple() to ptr_ring_resize_multiple_bh() - skb_array_resize_multiple() to skb_array_resize_multiple_bh() [1] WARNING: CPU: 1 PID: 9150 at net/core/page_pool.c:709 __page_pool_put_page net/core/page_pool.c:709 [inline] WARNING: CPU: 1 PID: 9150 at net/core/page_pool.c:709 page_pool_put_unrefed_netmem+0x157/0xa40 net/core/page_pool.c:780 Modules linked in: CPU: 1 UID: 0 PID: 9150 Comm: syz.1.1052 Not tainted 6.11.0-rc3-syzkaller-00202-gf8669d7b5f5d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:__page_pool_put_page net/core/page_pool.c:709 [inline] RIP: 0010:page_pool_put_unrefed_netmem+0x157/0xa40 net/core/page_pool.c:780 Code: 74 0e e8 7c aa fb f7 eb 43 e8 75 aa fb f7 eb 3c 65 8b 1d 38 a8 6a 76 31 ff 89 de e8 a3 ae fb f7 85 db 74 0b e8 5a aa fb f7 90 <0f> 0b 90 eb 1d 65 8b 1d 15 a8 6a 76 31 ff 89 de e8 84 ae fb f7 85 RSP: 0018:ffffc9000bda6b58 EFLAGS: 00010083 RAX: ffffffff8997e523 RBX: 0000000000000000 RCX: 0000000000040000 RDX: ffffc9000fbd0000 RSI: 0000000000001842 RDI: 0000000000001843 RBP: 0000000000000000 R08: ffffffff8997df2c R09: 1ffffd40003a000d R10: dffffc0000000000 R11: fffff940003a000e R12: ffffea0001d00040 R13: ffff88802e8a4000 R14: dffffc0000000000 R15: 00000000ffffffff FS: 00007fb7aaf716c0(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa15a0d4b72 CR3: 00000000561b0000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: tun_ptr_free drivers/net/tun.c:617 [inline] __ptr_ring_swap_queue include/linux/ptr_ring.h:571 [inline] ptr_ring_resize_multiple_noprof include/linux/ptr_ring.h:643 [inline] tun_queue_resize drivers/net/tun.c:3694 [inline] tun_device_event+0xaaf/0x1080 drivers/net/tun.c:3714 notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93 call_netdevice_notifiers_extack net/core/dev.c:2032 [inline] call_netdevice_notifiers net/core/dev.c:2046 [inline] dev_change_tx_queue_len+0x158/0x2a0 net/core/dev.c:9024 do_setlink+0xff6/0x41f0 net/core/rtnetlink.c:2923 rtnl_setlink+0x40d/0x5a0 net/core/rtnetlink.c:3201 rtnetlink_rcv_msg+0x73f/0xcf0 net/core/rtnetlink.c:6647 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2550 Fixes: ff4e538c8c3e ("page_pool: add a lockdep check for recycling in hardirq") Reported-by: syzbot+f56a5c5eac2b28439810@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/671e10df.050a0220.2b8c0f.01cf.GAE@google.com/T/ Signed-off-by: Eric Dumazet Acked-by: Michael S. Tsirkin Acked-by: Jason Wang Link: https://patch.msgid.link/20241217135121.326370-1-edumazet@google.com Signed-off-by: Jakub Kicinski --- drivers/net/tap.c | 6 +++--- drivers/net/tun.c | 6 +++--- include/linux/ptr_ring.h | 21 ++++++++++----------- include/linux/skb_array.h | 17 +++++++++-------- net/sched/sch_generic.c | 4 ++-- 5 files changed, 27 insertions(+), 27 deletions(-) diff --git a/drivers/net/tap.c b/drivers/net/tap.c index 5aa41d5f7765..5ca6ecf0ce5f 100644 --- a/drivers/net/tap.c +++ b/drivers/net/tap.c @@ -1329,9 +1329,9 @@ int tap_queue_resize(struct tap_dev *tap) list_for_each_entry(q, &tap->queue_list, next) rings[i++] = &q->ring; - ret = ptr_ring_resize_multiple(rings, n, - dev->tx_queue_len, GFP_KERNEL, - __skb_array_destroy_skb); + ret = ptr_ring_resize_multiple_bh(rings, n, + dev->tx_queue_len, GFP_KERNEL, + __skb_array_destroy_skb); kfree(rings); return ret; diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 8e94df88392c..41e3eeac06fd 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -3701,9 +3701,9 @@ static int tun_queue_resize(struct tun_struct *tun) list_for_each_entry(tfile, &tun->disabled, next) rings[i++] = &tfile->tx_ring; - ret = ptr_ring_resize_multiple(rings, n, - dev->tx_queue_len, GFP_KERNEL, - tun_ptr_free); + ret = ptr_ring_resize_multiple_bh(rings, n, + dev->tx_queue_len, GFP_KERNEL, + tun_ptr_free); kfree(rings); return ret; diff --git a/include/linux/ptr_ring.h b/include/linux/ptr_ring.h index fd037c127bb0..551329220e4f 100644 --- a/include/linux/ptr_ring.h +++ b/include/linux/ptr_ring.h @@ -615,15 +615,14 @@ static inline int ptr_ring_resize_noprof(struct ptr_ring *r, int size, gfp_t gfp /* * Note: producer lock is nested within consumer lock, so if you * resize you must make sure all uses nest correctly. - * In particular if you consume ring in interrupt or BH context, you must - * disable interrupts/BH when doing so. + * In particular if you consume ring in BH context, you must + * disable BH when doing so. */ -static inline int ptr_ring_resize_multiple_noprof(struct ptr_ring **rings, - unsigned int nrings, - int size, - gfp_t gfp, void (*destroy)(void *)) +static inline int ptr_ring_resize_multiple_bh_noprof(struct ptr_ring **rings, + unsigned int nrings, + int size, gfp_t gfp, + void (*destroy)(void *)) { - unsigned long flags; void ***queues; int i; @@ -638,12 +637,12 @@ static inline int ptr_ring_resize_multiple_noprof(struct ptr_ring **rings, } for (i = 0; i < nrings; ++i) { - spin_lock_irqsave(&(rings[i])->consumer_lock, flags); + spin_lock_bh(&(rings[i])->consumer_lock); spin_lock(&(rings[i])->producer_lock); queues[i] = __ptr_ring_swap_queue(rings[i], queues[i], size, gfp, destroy); spin_unlock(&(rings[i])->producer_lock); - spin_unlock_irqrestore(&(rings[i])->consumer_lock, flags); + spin_unlock_bh(&(rings[i])->consumer_lock); } for (i = 0; i < nrings; ++i) @@ -662,8 +661,8 @@ static inline int ptr_ring_resize_multiple_noprof(struct ptr_ring **rings, noqueues: return -ENOMEM; } -#define ptr_ring_resize_multiple(...) \ - alloc_hooks(ptr_ring_resize_multiple_noprof(__VA_ARGS__)) +#define ptr_ring_resize_multiple_bh(...) \ + alloc_hooks(ptr_ring_resize_multiple_bh_noprof(__VA_ARGS__)) static inline void ptr_ring_cleanup(struct ptr_ring *r, void (*destroy)(void *)) { diff --git a/include/linux/skb_array.h b/include/linux/skb_array.h index 926496c9cc9c..bf178238a308 100644 --- a/include/linux/skb_array.h +++ b/include/linux/skb_array.h @@ -199,17 +199,18 @@ static inline int skb_array_resize(struct skb_array *a, int size, gfp_t gfp) return ptr_ring_resize(&a->ring, size, gfp, __skb_array_destroy_skb); } -static inline int skb_array_resize_multiple_noprof(struct skb_array **rings, - int nrings, unsigned int size, - gfp_t gfp) +static inline int skb_array_resize_multiple_bh_noprof(struct skb_array **rings, + int nrings, + unsigned int size, + gfp_t gfp) { BUILD_BUG_ON(offsetof(struct skb_array, ring)); - return ptr_ring_resize_multiple_noprof((struct ptr_ring **)rings, - nrings, size, gfp, - __skb_array_destroy_skb); + return ptr_ring_resize_multiple_bh_noprof((struct ptr_ring **)rings, + nrings, size, gfp, + __skb_array_destroy_skb); } -#define skb_array_resize_multiple(...) \ - alloc_hooks(skb_array_resize_multiple_noprof(__VA_ARGS__)) +#define skb_array_resize_multiple_bh(...) \ + alloc_hooks(skb_array_resize_multiple_bh_noprof(__VA_ARGS__)) static inline void skb_array_cleanup(struct skb_array *a) { diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 38ec18f73de4..8874ae668095 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -911,8 +911,8 @@ static int pfifo_fast_change_tx_queue_len(struct Qdisc *sch, bands[prio] = q; } - return skb_array_resize_multiple(bands, PFIFO_FAST_BANDS, new_len, - GFP_KERNEL); + return skb_array_resize_multiple_bh(bands, PFIFO_FAST_BANDS, new_len, + GFP_KERNEL); } struct Qdisc_ops pfifo_fast_ops __read_mostly = {