From db973a7289dad24e6c017dcedc6aee886579dc3a Mon Sep 17 00:00:00 2001 From: Sudip Mukherjee Date: Mon, 20 Apr 2020 18:14:20 -0700 Subject: [PATCH] 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: 315c69261dd3 ("coredump: split pipe command whitespace before expanding template") Reported-by: Matthew Ruffell Signed-off-by: Sudip Mukherjee Signed-off-by: Andrew Morton Cc: Paul Wise Cc: Alexander Viro Cc: Neil Horman Cc: Link: http://lkml.kernel.org/r/20200416194612.21418-1-sudipm.mukherjee@gmail.com Signed-off-by: Linus Torvalds --- fs/coredump.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/coredump.c b/fs/coredump.c index f8296a82d01d..408418e6aa13 100644 --- a/fs/coredump.c +++ b/fs/coredump.c @@ -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 -- GitLab