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From: Andrew Morton <akpm@linux-foundation.org>
To: akpm@linux-foundation.org, linux-mm@kvack.org,
	matthew.ruffell@canonical.com, mm-commits@vger.kernel.org,
	nhorman@tuxdriver.com, pabs3@bonedaddy.net,
	stable@vger.kernel.org, sudipm.mukherjee@gmail.com,
	torvalds@linux-foundation.org, viro@zeniv.linux.org.uk
Subject: [patch 14/15] coredump: fix null pointer dereference on coredump
Date: Mon, 20 Apr 2020 18:14:20 -0700	[thread overview]
Message-ID: <20200421011420.GnVj8rZfk%akpm@linux-foundation.org> (raw)
In-Reply-To: <20200420181310.c18b3c0aa4dc5b3e5ec1be10@linux-foundation.org>

From: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Subject: coredump: fix null pointer dereference on coredump

If the core_pattern is set to "|" and any process segfaults then we get
a null pointer derefernce while trying to coredump. The call stack shows:
[  108.212680] RIP: 0010:do_coredump+0x628/0x11c0

When the core_pattern has only "|" there is no use of trying the coredump
and we can check that while formating the corename and exit with an error.

After this change I get:
[   48.453756] format_corename failed
[   48.453758] Aborting core

Link: http://lkml.kernel.org/r/20200416194612.21418-1-sudipm.mukherjee@gmail.com
Fixes: 315c69261dd3 ("coredump: split pipe command whitespace before expanding template")
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Reported-by: Matthew Ruffell <matthew.ruffell@canonical.com>
Cc: Paul Wise <pabs3@bonedaddy.net>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/coredump.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/fs/coredump.c~coredump-fix-null-pointer-dereference-on-coredump
+++ a/fs/coredump.c
@@ -211,6 +211,8 @@ static int format_corename(struct core_n
 			return -ENOMEM;
 		(*argv)[(*argc)++] = 0;
 		++pat_ptr;
+		if (!(*pat_ptr))
+			return -ENOMEM;
 	}
 
 	/* Repeat as long as we have more pattern to process and more output
_


  parent reply	other threads:[~2020-04-21  1:14 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-21  1:13 incoming Andrew Morton
2020-04-21  1:13 ` [patch 01/15] sh: fix build error in mm/init.c Andrew Morton
2020-04-21  1:13 ` [patch 02/15] slub: avoid redzone when choosing freepointer location Andrew Morton
2020-04-21  1:13 ` [patch 03/15] mm/userfaultfd: disable userfaultfd-wp on x86_32 Andrew Morton
2020-04-21  1:13 ` [patch 04/15] MAINTAINERS: add an entry for kfifo Andrew Morton
2020-04-21 12:31   ` Andy Shevchenko
2020-04-21  1:13 ` [patch 05/15] mm/hugetlb: fix a addressing exception caused by huge_pte_offset Andrew Morton
2020-04-21  1:13 ` [patch 06/15] mm, gup: return EINTR when gup is interrupted by fatal signals Andrew Morton
2020-04-21  1:13 ` [patch 07/15] checkpatch: fix a typo in the regex for $allocFunctions Andrew Morton
2020-04-21  1:14 ` [patch 08/15] tools/build: tweak unused value workaround Andrew Morton
2020-04-21  1:14 ` [patch 09/15] mm/ksm: fix NULL pointer dereference when KSM zero page is enabled Andrew Morton
2020-04-21  1:14 ` [patch 10/15] mm/shmem: fix build without THP Andrew Morton
2020-04-21  1:14 ` [patch 11/15] vmalloc: fix remap_vmalloc_range() bounds checks Andrew Morton
2020-04-21  1:14 ` [patch 12/15] shmem: fix possible deadlocks on shmlock_user_lock Andrew Morton
2020-04-21  1:14 ` [patch 13/15] mm: shmem: disable interrupt when acquiring info->lock in userfaultfd_copy path Andrew Morton
2020-04-21  1:14 ` Andrew Morton [this message]
2020-04-21  1:14 ` [patch 15/15] tools/vm: fix cross-compile build Andrew Morton
2020-04-21  5:43 ` mmotm 2020-04-20-22-43 uploaded Andrew Morton

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