| From bippy-1.2.0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@kernel.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2025-37896: spi: spi-mem: Add fix to avoid divide error |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| spi: spi-mem: Add fix to avoid divide error |
| |
| For some SPI flash memory operations, dummy bytes are not mandatory. For |
| example, in Winbond SPINAND flash memory devices, the `write_cache` and |
| `update_cache` operation variants have zero dummy bytes. Calculating the |
| duration for SPI memory operations with zero dummy bytes causes |
| a divide error when `ncycles` is calculated in the |
| spi_mem_calc_op_duration(). |
| |
| Add changes to skip the 'ncylcles' calculation for zero dummy bytes. |
| |
| Following divide error is fixed by this change: |
| |
| Oops: divide error: 0000 [#1] PREEMPT SMP NOPTI |
| ... |
| |
| ? do_trap+0xdb/0x100 |
| ? do_error_trap+0x75/0xb0 |
| ? spi_mem_calc_op_duration+0x56/0xb0 |
| ? exc_divide_error+0x3b/0x70 |
| ? spi_mem_calc_op_duration+0x56/0xb0 |
| ? asm_exc_divide_error+0x1b/0x20 |
| ? spi_mem_calc_op_duration+0x56/0xb0 |
| ? spinand_select_op_variant+0xee/0x190 [spinand] |
| spinand_match_and_init+0x13e/0x1a0 [spinand] |
| spinand_manufacturer_match+0x6e/0xa0 [spinand] |
| spinand_probe+0x357/0x7f0 [spinand] |
| ? kernfs_activate+0x87/0xd0 |
| spi_mem_probe+0x7a/0xb0 |
| spi_probe+0x7d/0x130 |
| |
| The Linux kernel CVE team has assigned CVE-2025-37896 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.14 with commit 226d6cb3cb799aae46d0dd19a521133997d9db11 and fixed in 6.14.6 with commit 1915dbd67dadc0bb35670c8e28229baa29368d17 |
| Issue introduced in 6.14 with commit 226d6cb3cb799aae46d0dd19a521133997d9db11 and fixed in 6.15 with commit 8e4d3d8a5e51e07bd0d6cdd81b5e4af79f796927 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2025-37896 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| drivers/spi/spi-mem.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/1915dbd67dadc0bb35670c8e28229baa29368d17 |
| https://git.kernel.org/stable/c/8e4d3d8a5e51e07bd0d6cdd81b5e4af79f796927 |
