Commit db973a72 authored Apr 20, 2020 by Sudip Mukherjee Committed by Linus Torvalds Apr 21, 2020

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:

    RIP: 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:

    format_corename failed
    Aborting core

Fixes: 315c6926 ("coredump: split pipe command whitespace before expanding template")
Reported-by: Matthew Ruffell <matthew.ruffell@canonical.com>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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>
Link: http://lkml.kernel.org/r/20200416194612.21418-1-sudipm.mukherjee@gmail.com


Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 94b7cc01

fs/coredump.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -211,6 +211,8 @@ static int format_corename(struct core_name cn, struct coredump_params cprm,
		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

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