[Crash-utility] [PATCH] netdump: bugfix for read elf header

From: Qianli Zhao <zhaoqianli(a)xiaomi.com&gt; Without the patch,errors may occur in reading the ELF header, causing the parsing to fail. Signed-off-by: Qianli Zhao <zhaoqianli(a)xiaomi.com&gt; --- When i use crash to parsing a kdump,i got below error. This error occurs because of the read header less then SAFE_NETDUMP_ELF_HEADER_SIZE, But can read MIN_NETDUMP_ELF_HEADER_SIZE bytes from the file correctly. this issue is introduced due to commit:f42db6a33f0e0652df7cce8506352745b4794287 crash 7.2.9 Copyright (C) 2002-2020 Red Hat, Inc. Copyright (C) 2004, 2005, 2006, 2010 IBM Corporation Copyright (C) 1999-2006 Hewlett-Packard Co Copyright (C) 2005, 2006, 2011, 2012 Fujitsu Limited Copyright (C) 2006, 2007 VA Linux Systems Japan K.K. Copyright (C) 2005, 2011 NEC Corporation Copyright (C) 1999, 2002, 2007 Silicon Graphics, Inc. Copyright (C) 1999, 2000, 2001, 2002 Mission Critical Linux, Inc. This program is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Enter "help copying" to see the conditions. This program has absolutely no warranty. Enter "help warranty" for details. /var/tmp/ramdump_elf_B2R4cQ: ELF header read: No such file or directory crash: malformed ELF file: /var/tmp/ramdump_elf_B2R4cQ Usage: crash [OPTION]... NAMELIST MEMORY-IMAGE[@ADDRESS] (dumpfile form) crash [OPTION]... [NAMELIST] (live system form) Enter "crash -h" for details. --- netdump.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/netdump.c b/netdump.c index c76d9dd..cb0af41 100644 --- a/netdump.c +++ b/netdump.c @@ -142,7 +142,7 @@ is_netdump(char *file, ulong source_query) if (!read_flattened_format(fd, 0, eheader, size)) goto bailout; } else { - if (read(fd, eheader, size) != size) { + if (read(fd, eheader, size) < MIN_NETDUMP_ELF_HEADER_SIZE) { sprintf(buf, "%s: ELF header read", file); perror(buf); goto bailout; -- 2.7.4