CVE-2024-35920

In the Linux kernel, the following vulnerability has been resolved:

media: mediatek: vcodec: adding lock to protect decoder context list

Add a lock for the ctx_list, to avoid accessing a NULL pointer

within the 'vpu_dec_ipi_handler' function when the ctx_list has

been deleted due to an unexpected behavior on the SCP IP block.

Hardware name: Google juniper sku16 board (DT)

pstate: 20400005 (nzCv daif +PAN -UAO -TCO BTYPE=--)

pc : vpu_dec_ipi_handler+0x58/0x1f8 [mtk_vcodec_dec]

lr : scp_ipi_handler+0xd0/0x194 [mtk_scp]

sp : ffffffc0131dbbd0

x29: ffffffc0131dbbd0 x28: 0000000000000000

x27: ffffff9bb277f348 x26: ffffff9bb242ad00

x25: ffffffd2d440d3b8 x24: ffffffd2a13ff1d4

x23: ffffff9bb7fe85a0 x22: ffffffc0133fbdb0

x21: 0000000000000010 x20: ffffff9b050ea328

x19: ffffffc0131dbc08 x18: 0000000000001000

x17: 0000000000000000 x16: ffffffd2d461c6e0

x15: 0000000000000242 x14: 000000000000018f

x13: 000000000000004d x12: 0000000000000000

x11: 0000000000000001 x10: fffffffffffffff0

x9 : ffffff9bb6e793a8 x8 : 0000000000000000

x7 : 0000000000000000 x6 : 000000000000003f

x5 : 0000000000000040 x4 : fffffffffffffff0

x3 : 0000000000000020 x2 : ffffff9bb6e79080

x1 : 0000000000000010 x0 : ffffffc0131dbc08

Call trace:

vpu_dec_ipi_handler+0x58/0x1f8 [mtk_vcodec_dec (HASH:6c3f 2)]

scp_ipi_handler+0xd0/0x194 [mtk_scp (HASH:7046 3)]

mt8183_scp_irq_handler+0x44/0x88 [mtk_scp (HASH:7046 3)]

scp_irq_handler+0x48/0x90 [mtk_scp (HASH:7046 3)]

irq_thread_fn+0x38/0x94

irq_thread+0x100/0x1c0

kthread+0x140/0x1fc

ret_from_fork+0x10/0x30

Code: 54000088 f94ca50a eb14015f 54000060 (f9400108)

---[ end trace ace43ce36cbd5c93 ]---

Kernel panic - not syncing: Oops: Fatal exception

SMP: stopping secondary CPUs

Kernel Offset: 0x12c4000000 from 0xffffffc010000000

PHYS_OFFSET: 0xffffffe580000000

CPU features: 0x08240002,2188200c

Memory Limit: none