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authorRichard Yao <[email protected]>2022-10-20 17:52:35 -0400
committerGitHub <[email protected]>2022-10-20 14:52:35 -0700
commit72a366f0181e541d62c776dbefd12e01f7afd216 (patch)
tree4a94d3e8150225878f8c04fbaec09f713b7c2b9e /lib
parentab32a14b2ed7531a76fd13a5278dd7d47d2ee923 (diff)
Linux: Fix big endian and partial read bugs in get_system_hostid()
Coverity made two complaints about this function. The first is that we ignore the number of bytes read. The second is that we have a sizeof mismatch. On 64-bit systems, long is a 64-bit type. Paradoxically, the standard says that hostid is 32-bit, yet is also a long type. On 64-bit big endian systems, reading into the long would cause us to return 0 as our hostid after the mask. This is wrong. Also, if a partial read were to happen (it should not), we would return a partial hostid, which is also wrong. We introduce a uint32_t system_hostid stack variable and ensure that the read is done into it and check the read's return value. Then we set the value based on whether the read was successful. This should fix both of coverity's complaints. Reviewed-by: Brian Behlendorf <[email protected]> Reviewed-by: Neal Gompa <[email protected]> Signed-off-by: Richard Yao <[email protected]> Closes #13968
Diffstat (limited to 'lib')
-rw-r--r--lib/libspl/os/linux/gethostid.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/lib/libspl/os/linux/gethostid.c b/lib/libspl/os/linux/gethostid.c
index 4f0f73c89..fcef8798c 100644
--- a/lib/libspl/os/linux/gethostid.c
+++ b/lib/libspl/os/linux/gethostid.c
@@ -59,6 +59,7 @@ unsigned long
get_system_hostid(void)
{
unsigned long hostid = get_spl_hostid();
+ uint32_t system_hostid;
/*
* We do not use gethostid(3) because it can return a bogus ID,
@@ -69,8 +70,11 @@ get_system_hostid(void)
if (hostid == 0) {
int fd = open("/etc/hostid", O_RDONLY | O_CLOEXEC);
if (fd >= 0) {
- if (read(fd, &hostid, 4) < 0)
+ if (read(fd, &system_hostid, sizeof (system_hostid))
+ != sizeof (system_hostid))
hostid = 0;
+ else
+ hostid = system_hostid;
(void) close(fd);
}
}