From: Eric Dumazet <eric.dumazet@gmail•com>
To: "David S . Miller" <davem@davemloft•net>,
Jakub Kicinski <kuba@kernel•org>
Cc: netdev <netdev@vger•kernel.org>,
Eric Dumazet <edumazet@google•com>,
Eric Dumazet <eric.dumazet@gmail•com>,
Dmitry Vyukov <dvyukov@google•com>,
syzbot <syzkaller@googlegroups•com>
Subject: [PATCH net] ref_tracker: use __GFP_NOFAIL more carefully
Date: Wed, 12 Jan 2022 03:14:45 -0800 [thread overview]
Message-ID: <20220112111445.486446-1-eric.dumazet@gmail.com> (raw)
From: Eric Dumazet <edumazet@google•com>
syzbot was able to trigger this warning from new_slab()
/*
* All existing users of the __GFP_NOFAIL are blockable, so warn
* of any new users that actually require GFP_NOWAIT
*/
if (WARN_ON_ONCE(!can_direct_reclaim))
goto fail;
Indeed, we should use __GFP_NOFAIL if direct reclaim is possible.
Hopefully in the future we will be able to use SLAB_NOFAILSLAB
option so that syzbot can benefit from full ref_tracker
even in the presence of memory fault injections.
WARNING: CPU: 0 PID: 13 at mm/page_alloc.c:5081 __alloc_pages_slowpath.constprop.0+0x1b7b/0x20d0 mm/page_alloc.c:5081 mm/page_alloc.c:5081
Modules linked in:
CPU: 0 PID: 13 Comm: ksoftirqd/0 Not tainted 5.16.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__alloc_pages_slowpath.constprop.0+0x1b7b/0x20d0 mm/page_alloc.c:5081 mm/page_alloc.c:5081
Code: 90 08 00 00 48 81 c7 d8 04 00 00 48 89 f8 48 c1 e8 03 42 80 3c 30 00 0f 84 f0 ea ff ff e8 3d 82 09 00 e9 e6 ea ff ff 4d 89 fd <0f> 0b 48 b8 00 00 00 00 00 fc ff df 48 8b 54 24 30 48 c1 ea 03 80
RSP: 0018:ffffc90000d272b8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88813fffc300 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffff88813fffc348
RBP: ffff88813fffc300 R08: 00000000000013dc R09: 00000000000013c8
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffffc90000d274e8 R14: dffffc0000000000 R15: ffffc90000d274e8
FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffefe6000f8 CR3: 000000001d21e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__alloc_pages+0x412/0x500 mm/page_alloc.c:5382 mm/page_alloc.c:5382
alloc_pages+0x1a7/0x300 mm/mempolicy.c:2191 mm/mempolicy.c:2191
alloc_slab_page mm/slub.c:1793 [inline]
allocate_slab mm/slub.c:1938 [inline]
alloc_slab_page mm/slub.c:1793 [inline] mm/slub.c:1993
allocate_slab mm/slub.c:1938 [inline] mm/slub.c:1993
new_slab+0x349/0x4a0 mm/slub.c:1993 mm/slub.c:1993
___slab_alloc+0x918/0xfe0 mm/slub.c:3022 mm/slub.c:3022
__slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3109 mm/slub.c:3109
slab_alloc_node mm/slub.c:3200 [inline]
slab_alloc mm/slub.c:3242 [inline]
slab_alloc_node mm/slub.c:3200 [inline] mm/slub.c:3259
slab_alloc mm/slub.c:3242 [inline] mm/slub.c:3259
kmem_cache_alloc_trace+0x289/0x2c0 mm/slub.c:3259 mm/slub.c:3259
kmalloc include/linux/slab.h:590 [inline]
kzalloc include/linux/slab.h:724 [inline]
kmalloc include/linux/slab.h:590 [inline] lib/ref_tracker.c:74
kzalloc include/linux/slab.h:724 [inline] lib/ref_tracker.c:74
ref_tracker_alloc+0xe1/0x430 lib/ref_tracker.c:74 lib/ref_tracker.c:74
netdev_tracker_alloc include/linux/netdevice.h:3855 [inline]
dev_hold_track include/linux/netdevice.h:3872 [inline]
netdev_tracker_alloc include/linux/netdevice.h:3855 [inline] net/core/dst.c:52
dev_hold_track include/linux/netdevice.h:3872 [inline] net/core/dst.c:52
dst_init+0xe0/0x520 net/core/dst.c:52 net/core/dst.c:52
dst_alloc+0x16b/0x1f0 net/core/dst.c:96 net/core/dst.c:96
rt_dst_alloc+0x73/0x450 net/ipv4/route.c:1614 net/ipv4/route.c:1614
ip_route_input_mc net/ipv4/route.c:1720 [inline]
ip_route_input_mc net/ipv4/route.c:1720 [inline] net/ipv4/route.c:2465
ip_route_input_rcu.part.0+0x4fe/0xcc0 net/ipv4/route.c:2465 net/ipv4/route.c:2465
ip_route_input_rcu net/ipv4/route.c:2420 [inline]
ip_route_input_rcu net/ipv4/route.c:2420 [inline] net/ipv4/route.c:2416
ip_route_input_noref+0x1b8/0x2a0 net/ipv4/route.c:2416 net/ipv4/route.c:2416
ip_rcv_finish_core.constprop.0+0x288/0x1e90 net/ipv4/ip_input.c:354 net/ipv4/ip_input.c:354
ip_rcv_finish+0x135/0x2f0 net/ipv4/ip_input.c:427 net/ipv4/ip_input.c:427
NF_HOOK include/linux/netfilter.h:307 [inline]
NF_HOOK include/linux/netfilter.h:301 [inline]
NF_HOOK include/linux/netfilter.h:307 [inline] net/ipv4/ip_input.c:540
NF_HOOK include/linux/netfilter.h:301 [inline] net/ipv4/ip_input.c:540
ip_rcv+0xaa/0xd0 net/ipv4/ip_input.c:540 net/ipv4/ip_input.c:540
__netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5350 net/core/dev.c:5350
__netif_receive_skb+0x24/0x1b0 net/core/dev.c:5464 net/core/dev.c:5464
process_backlog+0x2a5/0x6c0 net/core/dev.c:5796 net/core/dev.c:5796
__napi_poll+0xaf/0x440 net/core/dev.c:6364 net/core/dev.c:6364
napi_poll net/core/dev.c:6431 [inline]
napi_poll net/core/dev.c:6431 [inline] net/core/dev.c:6518
net_rx_action+0x801/0xb40 net/core/dev.c:6518 net/core/dev.c:6518
__do_softirq+0x29b/0x9c2 kernel/softirq.c:558 kernel/softirq.c:558
run_ksoftirqd kernel/softirq.c:921 [inline]
run_ksoftirqd kernel/softirq.c:921 [inline] kernel/softirq.c:913
run_ksoftirqd+0x2d/0x60 kernel/softirq.c:913 kernel/softirq.c:913
smpboot_thread_fn+0x645/0x9c0 kernel/smpboot.c:164 kernel/smpboot.c:164
kthread+0x405/0x4f0 kernel/kthread.c:327 kernel/kthread.c:327
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 arch/x86/entry/entry_64.S:295
Fixes: 4e66934eaadc ("lib: add reference counting tracking infrastructure")
Signed-off-by: Eric Dumazet <edumazet@google•com>
Cc: Dmitry Vyukov <dvyukov@google•com>
Reported-by: syzbot <syzkaller@googlegroups•com>
---
lib/ref_tracker.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/lib/ref_tracker.c b/lib/ref_tracker.c
index 0ae2e66dcf0fdb976f4cb99e747c9448b37f22cc..a6789c0c626b0f68ad67c264cd19177a63fb82d2 100644
--- a/lib/ref_tracker.c
+++ b/lib/ref_tracker.c
@@ -69,9 +69,12 @@ int ref_tracker_alloc(struct ref_tracker_dir *dir,
unsigned long entries[REF_TRACKER_STACK_ENTRIES];
struct ref_tracker *tracker;
unsigned int nr_entries;
+ gfp_t gfp_mask = gfp;
unsigned long flags;
- *trackerp = tracker = kzalloc(sizeof(*tracker), gfp | __GFP_NOFAIL);
+ if (gfp & __GFP_DIRECT_RECLAIM)
+ gfp_mask |= __GFP_NOFAIL;
+ *trackerp = tracker = kzalloc(sizeof(*tracker), gfp_mask);
if (unlikely(!tracker)) {
pr_err_once("memory allocation failure, unreliable refcount tracker.\n");
refcount_inc(&dir->untracked);
--
2.34.1.575.g55b058a8bb-goog
next reply other threads:[~2022-01-12 11:14 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-12 11:14 Eric Dumazet [this message]
2022-01-12 14:40 ` [PATCH net] ref_tracker: use __GFP_NOFAIL more carefully patchwork-bot+netdevbpf
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