The patch titled
Subject: kernel/exit.c: avoid undefined behaviour when calling wait4()
has been added to the -mm tree. Its filename is
exit-avoid-undefined-behaviour-when-call-wait4.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/exit-avoid-undefined-behaviour-when-call-wait4.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/exit-avoid-undefined-behaviour-when-call-wait4.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: zhongjiang <zhongjiang@xxxxxxxxxx>
Subject: kernel/exit.c: avoid undefined behaviour when calling wait4()
wait4(-2147483648, 0x20, 0, 0xdd0000) triggers:
UBSAN: Undefined behaviour in kernel/exit.c:1651:9
The related calltrace is as follows:
[518871.435738] negation of -2147483648 cannot be represented in type 'int':
[518871.442618] CPU: 9 PID: 16482 Comm: zj Tainted: G B ---- ------- 3.10.0-327.53.58.71.x86_64+ #66
[518871.452874] Hardware name: Huawei Technologies Co., Ltd. Tecal RH2285 /BC11BTSA , BIOS CTSAV036 04/27/2011
[518871.464690] ffffffff82599190 000000008b740a25 ffff880112447d90 ffffffff81d6eb16
[518871.472395] ffff880112447da8 ffffffff81d6ebc9 ffffffff82599180 ffff880112447e98
[518871.480101] ffffffff81d6fc99 0000000041b58ab3 ffffffff8228d698 ffffffff81d6fb90
[518871.487801] Call Trace:
[518871.490435] [<ffffffff81d6eb16>] dump_stack+0x19/0x1b
[518871.495751] [<ffffffff81d6ebc9>] ubsan_epilogue+0xd/0x50
[518871.501328] [<ffffffff81d6fc99>] __ubsan_handle_negate_overflow+0x109/0x14e
[518871.508548] [<ffffffff81d6fb90>] ? __ubsan_handle_divrem_overflow+0x1df/0x1df
[518871.516041] [<ffffffff8116e0d4>] ? lg_local_lock+0x24/0xb0
[518871.521785] [<ffffffff8116e640>] ? lg_local_unlock+0x20/0xd0
[518871.527708] [<ffffffff81366fa0>] ? __pmd_alloc+0x180/0x180
[518871.533458] [<ffffffff8143f81b>] ? mntput+0x3b/0x70
[518871.538598] [<ffffffff8110d7bb>] SyS_wait4+0x1cb/0x1e0
[518871.543999] [<ffffffff8110d5f0>] ? SyS_waitid+0x220/0x220
[518871.549661] [<ffffffff8123bb57>] ? __audit_syscall_entry+0x1f7/0x2a0
[518871.556278] [<ffffffff81d91109>] system_call_fastpath+0x16/0x1b
Exclude the overflow to avoid the UBSAN warning.
Link: http://lkml.kernel.org/r/1497264618-20212-1-git-send-email-zhongjiang@xxxxxxxxxx
Signed-off-by: zhongjiang <zhongjiang@xxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Xishi Qiu <qiuxishi@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/exit.c | 4 ++++
1 file changed, 4 insertions(+)
diff -puN kernel/exit.c~exit-avoid-undefined-behaviour-when-call-wait4 kernel/exit.c
--- a/kernel/exit.c~exit-avoid-undefined-behaviour-when-call-wait4
+++ a/kernel/exit.c
@@ -1697,6 +1697,10 @@ SYSCALL_DEFINE4(wait4, pid_t, upid, int
__WNOTHREAD|__WCLONE|__WALL))
return -EINVAL;
+ /* -INT_MIN is not defined */
+ if (upid == INT_MIN)
+ return -ESRCH;
+
if (upid == -1)
type = PIDTYPE_MAX;
else if (upid < 0) {
_
Patches currently in -mm which might be from zhongjiang@xxxxxxxxxx are
mm-page_owner-align-with-pageblock_nr-pages.patch
mm-walk-the-zone-in-pageblock_nr_pages-steps.patch
signal-avoid-undefined-behaviour-in-kill_something_info.patch
exit-avoid-undefined-behaviour-when-call-wait4.patch
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