Description
In the Linux kernel, the following vulnerability has been resolved: accel/ethosu: fix OOB write in ethosu_gem_cmdstream_copy_and_validate() The command stream parsing loop increments the index variable a second time when a 64-bit command word is encountered (bit 14 set), but does not re-check the loop bound before writing the second word: for (i = 0; i < size / 4; i++) { bocmds[i] = cmds[0]; if (cmd & 0x4000) { i++; bocmds[i] = cmds[1]; /* unchecked */ } } The buffer bocmds is backed by a DMA allocation of exactly size bytes from drm_gem_dma_create(ddev, size), giving valid indices [0, size/4-1]. When i == size/4 - 1 on entry to an iteration and bit 14 of cmds[0] is set, bocmds[size/4-1] is written in bounds, i is then incremented to size/4, and bocmds[size/4] writes four bytes past the end of the allocation. Userspace controls both the buffer contents and the size argument via the ioctl, making this a userspace-triggerable heap out-of-bounds write. Fix by checking the incremented index against the buffer bound before the second write and returning -EINVAL if the buffer is too small to contain the extended command.
CVSS breakdown
Affected products
- Linux / Linux5a5e9c0228e613f0ef2a58b9782d7c0ea8f1e58b – db6cb3e35cebf487f9a78ebd4cfa4b83708ff40d
- Linux / Linux5a5e9c0228e613f0ef2a58b9782d7c0ea8f1e58b – c0837b9cf6eabbad8b8cbddaff1a46a6d0a2e29d
- Linux / Linux6.19 – 6.19
- Linux / Linux0 – 6.19
- Linux / Linux7.0.13 – 7.0.*
- Linux / Linux7.1 – *