From e873c74132f0c5f1452816cd9bb26208f0bba1e1 Mon Sep 17 00:00:00 2001 From: Shivank Garg Date: Sat, 22 Aug 2026 19:22:05 +0000 Subject: dmaengine: fix use-after-free in dma_chan_put() and dma_release_channel() When dma_device_put() drops the last reference on chan->device->ref, dma_device_release() runs and may free the dma_device along with its channels. dma_chan_put() then still reads chan->device->owner via dma_chan_to_owner() for the trailing module_put(). KASAN catches it: slab-use-after-free in dma_chan_put+0x3e6/0x4c0 Read of size 8 by task insmod/6319 Freed by task 6319: kfree+0x225/0x470 dma_chan_put+0x395/0x4c0 dmaengine_put+0xf8/0x160 Cache the module owner in dma_chan_put() before the put so the trailing module_put() does not need chan->device. Fixes: 8ad342a86359 ("dmaengine: Add reference counting to dma_device struct") Suggested-by: Sashiko Link: https://sashiko.dev/#/patchset/20260518-dmaengine-kref-fix-v1-1-4d6125048fb7@amd.com Reviewed-by: Frank Li Reviewed-by: Logan Gunthorpe Signed-off-by: Shivank Garg Link: https://patch.msgid.link/20260822-dmaengine-kref-fix-v5-3-d4a4ee47d927@amd.com Signed-off-by: Vinod Koul --- fs/udf/udftime.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 89 insertions(+) create mode 100644 fs/udf/udftime.c (limited to 'fs/udf/udftime.c') diff --git a/fs/udf/udftime.c b/fs/udf/udftime.c new file mode 100644 index 000000000..78ecc6336 --- /dev/null +++ b/fs/udf/udftime.c @@ -0,0 +1,89 @@ +// SPDX-License-Identifier: LGPL-2.0+ +/* Copyright (C) 1993, 1994, 1995, 1996, 1997 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Paul Eggert (eggert@twinsun.com). */ + +/* + * dgb 10/02/98: ripped this from glibc source to help convert timestamps + * to unix time + * 10/04/98: added new table-based lookup after seeing how ugly + * the gnu code is + * blf 09/27/99: ripped out all the old code and inserted new table from + * John Brockmeyer (without leap second corrections) + * rewrote udf_stamp_to_time and fixed timezone accounting in + * udf_time_to_stamp. + */ + +/* + * We don't take into account leap seconds. This may be correct or incorrect. + * For more NIST information (especially dealing with leap seconds), see: + * http://www.boulder.nist.gov/timefreq/pubs/bulletin/leapsecond.htm + */ + +#include "udfdecl.h" + +#include +#include +#include + +void +udf_disk_stamp_to_time(struct timespec64 *dest, struct timestamp src) +{ + u16 typeAndTimezone = le16_to_cpu(src.typeAndTimezone); + u16 year = le16_to_cpu(src.year); + uint8_t type = typeAndTimezone >> 12; + int16_t offset; + + if (type == 1) { + offset = typeAndTimezone << 4; + /* sign extent offset */ + offset = (offset >> 4); + if (offset == -2047) /* unspecified offset */ + offset = 0; + } else + offset = 0; + + dest->tv_sec = mktime64(year, src.month, src.day, src.hour, src.minute, + src.second); + dest->tv_sec -= offset * 60; + + /* + * Sanitize nanosecond field since reportedly some filesystems are + * recorded with bogus sub-second values. + */ + if (src.centiseconds < 100 && src.hundredsOfMicroseconds < 100 && + src.microseconds < 100) { + dest->tv_nsec = 1000 * (src.centiseconds * 10000 + + src.hundredsOfMicroseconds * 100 + src.microseconds); + } else { + dest->tv_nsec = 0; + } +} + +void +udf_time_to_disk_stamp(struct timestamp *dest, struct timespec64 ts) +{ + time64_t seconds; + int16_t offset; + struct tm tm; + + offset = -sys_tz.tz_minuteswest; + + dest->typeAndTimezone = cpu_to_le16(0x1000 | (offset & 0x0FFF)); + + seconds = ts.tv_sec + offset * 60; + time64_to_tm(seconds, 0, &tm); + dest->year = cpu_to_le16(tm.tm_year + 1900); + dest->month = tm.tm_mon + 1; + dest->day = tm.tm_mday; + dest->hour = tm.tm_hour; + dest->minute = tm.tm_min; + dest->second = tm.tm_sec; + dest->centiseconds = ts.tv_nsec / 10000000; + dest->hundredsOfMicroseconds = (ts.tv_nsec / 1000 - + dest->centiseconds * 10000) / 100; + dest->microseconds = (ts.tv_nsec / 1000 - dest->centiseconds * 10000 - + dest->hundredsOfMicroseconds * 100); +} + +/* EOF */ -- cgit v1.3.1