diff options
| author | Dmitry Vyukov <dvyukov@google.com> | 2019-07-12 06:53:39 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-07-12 21:05:42 +0300 |
| commit | 6ef9056952532c3b746de46aa10d45b4d7797bd8 (patch) | |
| tree | 8b24d892c4e96e659a468f3e605db0dbb6be65de /mm/kmemleak.c | |
| parent | cb097cd48313575b03a5de092a04f6af8aa0739e (diff) | |
| download | linux-6ef9056952532c3b746de46aa10d45b4d7797bd8.tar.xz | |
mm/kmemleak.c: fix check for softirq context
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>
Diffstat (limited to 'mm/kmemleak.c')
| -rw-r--r-- | mm/kmemleak.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 9dd581d11565..3e147ea83182 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -575,7 +575,7 @@ 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 { |