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| 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/alpha/boot/head.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/alpha/boot/head.S')
| -rw-r--r-- | arch/alpha/boot/head.S | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/arch/alpha/boot/head.S b/arch/alpha/boot/head.S new file mode 100644 index 000000000..06a7c95fe --- /dev/null +++ b/arch/alpha/boot/head.S @@ -0,0 +1,124 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * arch/alpha/boot/head.S + * + * initial bootloader stuff.. + */ + +#include <asm/pal.h> + + .set noreorder + .globl __start + .ent __start +__start: + br $29,2f +2: ldgp $29,0($29) + jsr $26,start_kernel + call_pal PAL_halt + .end __start + + .align 5 + .globl wrent + .ent wrent +wrent: + .prologue 0 + call_pal PAL_wrent + ret ($26) + .end wrent + + .align 5 + .globl wrkgp + .ent wrkgp +wrkgp: + .prologue 0 + call_pal PAL_wrkgp + ret ($26) + .end wrkgp + + .align 5 + .globl switch_to_osf_pal + .ent switch_to_osf_pal +switch_to_osf_pal: + subq $30,128,$30 + .frame $30,128,$26 + stq $26,0($30) + stq $1,8($30) + stq $2,16($30) + stq $3,24($30) + stq $4,32($30) + stq $5,40($30) + stq $6,48($30) + stq $7,56($30) + stq $8,64($30) + stq $9,72($30) + stq $10,80($30) + stq $11,88($30) + stq $12,96($30) + stq $13,104($30) + stq $14,112($30) + stq $15,120($30) + .prologue 0 + + stq $30,0($17) /* save KSP in PCB */ + + bis $30,$30,$20 /* a4 = KSP */ + br $17,1f + + ldq $26,0($30) + ldq $1,8($30) + ldq $2,16($30) + ldq $3,24($30) + ldq $4,32($30) + ldq $5,40($30) + ldq $6,48($30) + ldq $7,56($30) + ldq $8,64($30) + ldq $9,72($30) + ldq $10,80($30) + ldq $11,88($30) + ldq $12,96($30) + ldq $13,104($30) + ldq $14,112($30) + ldq $15,120($30) + addq $30,128,$30 + ret ($26) +1: call_pal PAL_swppal + .end switch_to_osf_pal + + .align 3 + .globl tbi + .ent tbi +tbi: + .prologue 0 + call_pal PAL_tbi + ret ($26) + .end tbi + + .align 3 + .globl halt + .ent halt +halt: + .prologue 0 + call_pal PAL_halt + .end halt + +/* $16 - new stack page */ + .align 3 + .globl move_stack + .ent move_stack +move_stack: + .prologue 0 + lda $0, 0x1fff($31) + and $0, $30, $1 /* Stack offset */ + or $1, $16, $16 /* New stack pointer */ + mov $30, $1 + mov $16, $2 +1: ldq $3, 0($1) /* Move the stack */ + addq $1, 8, $1 + stq $3, 0($2) + and $0, $1, $4 + addq $2, 8, $2 + bne $4, 1b + mov $16, $30 + ret ($26) + .end move_stack |