linux-kernel - [PATCH][next] kexec_file: Assign array

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Message-ID: <20200710212206.GA29369@embeddedor>
Date:   Fri, 10 Jul 2020 16:22:06 -0500
From:   "Gustavo A. R. Silva" <gustavoars@...nel.org>
To:     Eric Biederman <ebiederm@...ssion.com>
Cc:     kexec@...ts.infradead.org, linux-kernel@...r.kernel.org,
        "Gustavo A. R. Silva" <gustavo@...eddedor.com>
Subject: [PATCH][next] kexec_file: Assign array_size() to a variable

Assign array_size() to variable _size_ and use it in both vzalloc()
and memcpy(). These sorts of multiplication factors need to be wrapped
in array_size().

This issue was found with the help of Coccinelle and, audited and fixed
manually.

Signed-off-by: Gustavo A. R. Silva <gustavoars@...nel.org>
---
 kernel/kexec_file.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 09cc78df53c6..4479d864aaf2 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -883,16 +883,16 @@ static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi,
 	unsigned long offset;
 	Elf_Shdr *sechdrs;
 	int i;
+	size_t size = array_size(sizeof(Elf_Shdr), pi->ehdr->e_shnum);
 
 	/*
 	 * The section headers in kexec_purgatory are read-only. In order to
 	 * have them modifiable make a temporary copy.
 	 */
-	sechdrs = vzalloc(array_size(sizeof(Elf_Shdr), pi->ehdr->e_shnum));
+	sechdrs = vzalloc(size);
 	if (!sechdrs)
 		return -ENOMEM;
-	memcpy(sechdrs, (void *)pi->ehdr + pi->ehdr->e_shoff,
-	       pi->ehdr->e_shnum * sizeof(Elf_Shdr));
+	memcpy(sechdrs, (void *)pi->ehdr + pi->ehdr->e_shoff, size);
 	pi->sechdrs = sechdrs;
 
 	offset = 0;
-- 
2.27.0