x86/amd_node: Fix PCI device reference counting in amd_smn_init()grafted

The local "root" pointer is a temporary variable used during the device
search. Therefore, refcount related to the search iterators should be cleaned
up after the search is complete.

Use the __free() cleanup macro to ensure the refcount is decremented when the
temporary pointer goes out of scope.

Additionally, increment the refcount when caching a root pointer. This ensures
the in-use refcount is separate from the temporary search refcounting.

Finally, drop the redundant "root = NULL" before the second search loop. The
pci_get_class() iterator always decrements the refcount of its "from"
argument, so the first loop can only fall through with "root" already NULL.

Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching")
Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com
Reported-by: Sashiko <sashiko-bot@kernel.org>
Assisted-by: LLM
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Cc: <stable@kernel.org>
Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com

1 files changed, 86 insertions, 0 deletions

diff --git a/fs/isofs/util.c b/fs/isofs/util.c
new file mode 100644
index 000000000..42f479da0
--- /dev/null
+++ b/fs/isofs/util.c
@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/isofs/util.c
+ */
+
+#include <linux/time.h>
+#include "isofs.h"
+
+/* 
+ * We have to convert from a MM/DD/YY format to the Unix ctime format.
+ * We have to take into account leap years and all of that good stuff.
+ * Unfortunately, the kernel does not have the information on hand to
+ * take into account daylight savings time, but it shouldn't matter.
+ * The time stored should be localtime (with or without DST in effect),
+ * and the timezone offset should hold the offset required to get back
+ * to GMT.  Thus  we should always be correct.
+ */
+
+struct timespec64 iso_date(u8 *p, int flags)
+{
+	int year, month, day, hour, minute, second, tz;
+	struct timespec64 ts;
+
+	if (flags & ISO_DATE_LONG_FORM) {
+		year = (p[0] - '0') * 1000 +
+		       (p[1] - '0') * 100 +
+		       (p[2] - '0') * 10 +
+		       (p[3] - '0') - 1900;
+		month = ((p[4] - '0') * 10 + (p[5] - '0'));
+		day = ((p[6] - '0') * 10 + (p[7] - '0'));
+		hour = ((p[8] - '0') * 10 + (p[9] - '0'));
+		minute = ((p[10] - '0') * 10 + (p[11] - '0'));
+		second = ((p[12] - '0') * 10 + (p[13] - '0'));
+		ts.tv_nsec = ((p[14] - '0') * 10 + (p[15] - '0')) * 10000000;
+		tz = p[16];
+	} else {
+		year = p[0];
+		month = p[1];
+		day = p[2];
+		hour = p[3];
+		minute = p[4];
+		second = p[5];
+		ts.tv_nsec = 0;
+		/* High sierra has no time zone */
+		tz = flags & ISO_DATE_HIGH_SIERRA ? 0 : p[6];
+	}
+
+	if (year < 0) {
+		ts.tv_sec = 0;
+	} else {
+		ts.tv_sec = mktime64(year+1900, month, day, hour, minute, second);
+
+		/* sign extend */
+		if (tz & 0x80)
+			tz |= (-1 << 8);
+
+		/* 
+		 * The timezone offset is unreliable on some disks,
+		 * so we make a sanity check.  In no case is it ever
+		 * more than 13 hours from GMT, which is 52*15min.
+		 * The time is always stored in localtime with the
+		 * timezone offset being what get added to GMT to
+		 * get to localtime.  Thus we need to subtract the offset
+		 * to get to true GMT, which is what we store the time
+		 * as internally.  On the local system, the user may set
+		 * their timezone any way they wish, of course, so GMT
+		 * gets converted back to localtime on the receiving
+		 * system.
+		 *
+		 * NOTE: mkisofs in versions prior to mkisofs-1.10 had
+		 * the sign wrong on the timezone offset.  This has now
+		 * been corrected there too, but if you are getting screwy
+		 * results this may be the explanation.  If enough people
+		 * complain, a user configuration option could be added
+		 * to add the timezone offset in with the wrong sign
+		 * for 'compatibility' with older discs, but I cannot see how
+		 * it will matter that much.
+		 *
+		 * Thanks to kuhlmav@elec.canterbury.ac.nz (Volker Kuhlmann)
+		 * for pointing out the sign error.
+		 */
+		if (-52 <= tz && tz <= 52)
+			ts.tv_sec -= tz * 15 * 60;
+	}
+	return ts;
+}