um: Remove use of asprinf in umid.c

asprintf is not compatible with the existing uml memory allocation
mechanism. Its use on the "user" side of UML results in a corrupt slab
state.

Fixes: 0d4e5ac7e7 ("um: remove uses of variable length arrays")
Cc: stable@vger.kernel.org
Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
This commit is contained in:
Anton Ivanov 2020-11-13 10:26:17 +00:00 committed by Richard Weinberger
parent 09041c92f0
commit 97be7ceaf7

View File

@ -137,20 +137,13 @@ static inline int is_umdir_used(char *dir)
{
char pid[sizeof("nnnnnnnnn")], *end, *file;
int dead, fd, p, n, err;
size_t filelen;
size_t filelen = strlen(dir) + sizeof("/pid") + 1;
err = asprintf(&file, "%s/pid", dir);
if (err < 0)
return 0;
file = malloc(filelen);
if (!file)
return -ENOMEM;
filelen = strlen(file);
n = snprintf(file, filelen, "%s/pid", dir);
if (n >= filelen) {
printk(UM_KERN_ERR "is_umdir_used - pid filename too long\n");
err = -E2BIG;
goto out;
}
snprintf(file, filelen, "%s/pid", dir);
dead = 0;
fd = open(file, O_RDONLY);