From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Dmitry Vyukov <dvyukov@google.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Sasha Levin <sashal@kernel.org>,
linux-mm@kvack.org
Subject: [PATCH AUTOSEL 4.19 088/101] mm/kmemleak.c: fix check for softirq context
Date: Fri, 19 Jul 2019 00:07:19 -0400 [thread overview]
Message-ID: <20190719040732.17285-88-sashal@kernel.org> (raw)
In-Reply-To: <20190719040732.17285-1-sashal@kernel.org>
From: Dmitry Vyukov <dvyukov@google.com>
[ Upstream commit 6ef9056952532c3b746de46aa10d45b4d7797bd8 ]
in_softirq() is a wrong predicate to check if we are in a softirq
context. It also returns true if we have BH disabled, so objects are
falsely stamped with "softirq" comm. The correct predicate is
in_serving_softirq().
If user does cat from /sys/kernel/debug/kmemleak previously they would
see this, which is clearly wrong, this is system call context (see the
comm):
unreferenced object 0xffff88805bd661c0 (size 64):
comm "softirq", pid 0, jiffies 4294942959 (age 12.400s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 ff ff ff ff 00 00 00 00 ................
00 00 00 00 00 00 00 00 01 00 00 00 00 00 00 00 ................
backtrace:
[<0000000007dcb30c>] kmemleak_alloc_recursive include/linux/kmemleak.h:55 [inline]
[<0000000007dcb30c>] slab_post_alloc_hook mm/slab.h:439 [inline]
[<0000000007dcb30c>] slab_alloc mm/slab.c:3326 [inline]
[<0000000007dcb30c>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553
[<00000000969722b7>] kmalloc include/linux/slab.h:547 [inline]
[<00000000969722b7>] kzalloc include/linux/slab.h:742 [inline]
[<00000000969722b7>] ip_mc_add1_src net/ipv4/igmp.c:1961 [inline]
[<00000000969722b7>] ip_mc_add_src+0x36b/0x400 net/ipv4/igmp.c:2085
[<00000000a4134b5f>] ip_mc_msfilter+0x22d/0x310 net/ipv4/igmp.c:2475
[<00000000d20248ad>] do_ip_setsockopt.isra.0+0x19fe/0x1c00 net/ipv4/ip_sockglue.c:957
[<000000003d367be7>] ip_setsockopt+0x3b/0xb0 net/ipv4/ip_sockglue.c:1246
[<000000003c7c76af>] udp_setsockopt+0x4e/0x90 net/ipv4/udp.c:2616
[<000000000c1aeb23>] sock_common_setsockopt+0x3e/0x50 net/core/sock.c:3130
[<000000000157b92b>] __sys_setsockopt+0x9e/0x120 net/socket.c:2078
[<00000000a9f3d058>] __do_sys_setsockopt net/socket.c:2089 [inline]
[<00000000a9f3d058>] __se_sys_setsockopt net/socket.c:2086 [inline]
[<00000000a9f3d058>] __x64_sys_setsockopt+0x26/0x30 net/socket.c:2086
[<000000001b8da885>] do_syscall_64+0x7c/0x1a0 arch/x86/entry/common.c:301
[<00000000ba770c62>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
now they will see this:
unreferenced object 0xffff88805413c800 (size 64):
comm "syz-executor.4", pid 8960, jiffies 4294994003 (age 14.350s)
hex dump (first 32 bytes):
00 7a 8a 57 80 88 ff ff e0 00 00 01 00 00 00 00 .z.W............
00 00 00 00 00 00 00 00 01 00 00 00 00 00 00 00 ................
backtrace:
[<00000000c5d3be64>] kmemleak_alloc_recursive include/linux/kmemleak.h:55 [inline]
[<00000000c5d3be64>] slab_post_alloc_hook mm/slab.h:439 [inline]
[<00000000c5d3be64>] slab_alloc mm/slab.c:3326 [inline]
[<00000000c5d3be64>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553
[<0000000023865be2>] kmalloc include/linux/slab.h:547 [inline]
[<0000000023865be2>] kzalloc include/linux/slab.h:742 [inline]
[<0000000023865be2>] ip_mc_add1_src net/ipv4/igmp.c:1961 [inline]
[<0000000023865be2>] ip_mc_add_src+0x36b/0x400 net/ipv4/igmp.c:2085
[<000000003029a9d4>] ip_mc_msfilter+0x22d/0x310 net/ipv4/igmp.c:2475
[<00000000ccd0a87c>] do_ip_setsockopt.isra.0+0x19fe/0x1c00 net/ipv4/ip_sockglue.c:957
[<00000000a85a3785>] ip_setsockopt+0x3b/0xb0 net/ipv4/ip_sockglue.c:1246
[<00000000ec13c18d>] udp_setsockopt+0x4e/0x90 net/ipv4/udp.c:2616
[<0000000052d748e3>] sock_common_setsockopt+0x3e/0x50 net/core/sock.c:3130
[<00000000512f1014>] __sys_setsockopt+0x9e/0x120 net/socket.c:2078
[<00000000181758bc>] __do_sys_setsockopt net/socket.c:2089 [inline]
[<00000000181758bc>] __se_sys_setsockopt net/socket.c:2086 [inline]
[<00000000181758bc>] __x64_sys_setsockopt+0x26/0x30 net/socket.c:2086
[<00000000d4b73623>] do_syscall_64+0x7c/0x1a0 arch/x86/entry/common.c:301
[<00000000c1098bec>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
Link: http://lkml.kernel.org/r/20190517171507.96046-1-dvyukov@gmail.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
mm/kmemleak.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index 72e3fb3bb037..6c94b6865ac2 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -576,7 +576,7 @@ static struct kmemleak_object *create_object(unsigned long ptr, size_t size,
if (in_irq()) {
object->pid = 0;
strncpy(object->comm, "hardirq", sizeof(object->comm));
- } else if (in_softirq()) {
+ } else if (in_serving_softirq()) {
object->pid = 0;
strncpy(object->comm, "softirq", sizeof(object->comm));
} else {
--
2.20.1
next prev parent reply other threads:[~2019-07-19 4:10 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20190719040732.17285-1-sashal@kernel.org>
2019-07-19 4:06 ` [PATCH AUTOSEL 4.19 055/101] mm/swap: fix release_pages() when releasing devmap pages Sasha Levin
2019-07-19 4:07 ` Sasha Levin [this message]
2019-07-19 4:07 ` [PATCH AUTOSEL 4.19 090/101] mm/gup.c: mark undo_dev_pagemap as __maybe_unused Sasha Levin
2019-07-19 4:07 ` [PATCH AUTOSEL 4.19 091/101] mm/gup.c: remove some BUG_ONs from get_gate_page() Sasha Levin
2019-07-19 4:07 ` [PATCH AUTOSEL 4.19 093/101] mm/mmu_notifier: use hlist_add_head_rcu() Sasha Levin
2019-07-19 4:07 ` [PATCH AUTOSEL 4.19 101/101] mm: use down_read_killable for locking mmap_sem in access_remote_vm Sasha Levin
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