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/proc/interrupts.c | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 fs/proc/interrupts.c (limited to 'fs/proc/interrupts.c') diff --git a/fs/proc/interrupts.c b/fs/proc/interrupts.c new file mode 100644 index 000000000..714a22ded --- /dev/null +++ b/fs/proc/interrupts.c @@ -0,0 +1,42 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include + +/* + * /proc/interrupts + */ +static void *int_seq_start(struct seq_file *f, loff_t *pos) +{ + return *pos <= irq_get_nr_irqs() ? pos : NULL; +} + +static void *int_seq_next(struct seq_file *f, void *v, loff_t *pos) +{ + (*pos)++; + if (*pos > irq_get_nr_irqs()) + return NULL; + return pos; +} + +static void int_seq_stop(struct seq_file *f, void *v) +{ + /* Nothing to do */ +} + +static const struct seq_operations int_seq_ops = { + .start = int_seq_start, + .next = int_seq_next, + .stop = int_seq_stop, + .show = show_interrupts +}; + +static int __init proc_interrupts_init(void) +{ + proc_create_seq("interrupts", 0, NULL, &int_seq_ops); + return 0; +} +fs_initcall(proc_interrupts_init); -- cgit v1.3.1