diff options
| author | Shivank Garg <shivankg@amd.com> | 2026-08-22 19:22:05 +0000 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2026-09-09 17:51:44 +0530 |
| commit | e873c74132f0c5f1452816cd9bb26208f0bba1e1 (patch) | |
| tree | cc1ce1567f5b982359331863ebd9da38741f8d2e /arch/arc/lib/memset.S | |
| download | linux-stable-e873c74132f0c5f1452816cd9bb26208f0bba1e1.tar.gz linux-stable-e873c74132f0c5f1452816cd9bb26208f0bba1e1.zip | |
dmaengine: fix use-after-free in dma_chan_put() and dma_release_channel()grafted
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 <sashiko-bot@kernel.org>
Link: https://sashiko.dev/#/patchset/20260518-dmaengine-kref-fix-v1-1-4d6125048fb7@amd.com
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Shivank Garg <shivankg@amd.com>
Link: https://patch.msgid.link/20260822-dmaengine-kref-fix-v5-3-d4a4ee47d927@amd.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'arch/arc/lib/memset.S')
| -rw-r--r-- | arch/arc/lib/memset.S | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/arch/arc/lib/memset.S b/arch/arc/lib/memset.S new file mode 100644 index 000000000..9f35960da --- /dev/null +++ b/arch/arc/lib/memset.S @@ -0,0 +1,56 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) + */ + +#include <linux/linkage.h> + +#define SMALL 7 /* Must be at least 6 to deal with alignment/loop issues. */ + +ENTRY_CFI(memset) + mov_s r4,r0 + or r12,r0,r2 + bmsk.f r12,r12,1 + extb_s r1,r1 + asl r3,r1,8 + beq.d .Laligned + or_s r1,r1,r3 + brls r2,SMALL,.Ltiny + add r3,r2,r0 + stb r1,[r3,-1] + bclr_s r3,r3,0 + stw r1,[r3,-2] + bmsk.f r12,r0,1 + add_s r2,r2,r12 + sub.ne r2,r2,4 + stb.ab r1,[r4,1] + and r4,r4,-2 + stw.ab r1,[r4,2] + and r4,r4,-4 +.Laligned: ; This code address should be aligned for speed. + asl r3,r1,16 + lsr.f lp_count,r2,2 + or_s r1,r1,r3 + lpne .Loop_end + st.ab r1,[r4,4] +.Loop_end: + j_s [blink] + + .balign 4 +.Ltiny: + mov.f lp_count,r2 + lpne .Ltiny_end + stb.ab r1,[r4,1] +.Ltiny_end: + j_s [blink] +END_CFI(memset) + +; memzero: @r0 = mem, @r1 = size_t +; memset: @r0 = mem, @r1 = char, @r2 = size_t + +ENTRY_CFI(memzero) + ; adjust bzero args to memset args + mov r2, r1 + mov r1, 0 + b memset ;tail call so need to tinker with blink +END_CFI(memzero) |