CVE-2021-46959: spi: Fix use-after-free with devm_spi_alloc_*
First published: Thu Feb 29 2024(Updated: )
In the Linux kernel, the following vulnerability has been resolved: spi: Fix use-after-free with devm_spi_alloc_* We can't rely on the contents of the devres list during spi_unregister_controller(), as the list is already torn down at the time we perform devres_find() for devm_spi_release_controller. This causes devices registered with devm_spi_alloc_{master,slave}() to be mistakenly identified as legacy, non-devm managed devices and have their reference counters decremented below 0. ------------[ cut here ]------------ WARNING: CPU: 1 PID: 660 at lib/refcount.c:28 refcount_warn_saturate+0x108/0x174 [<b0396f04>] (refcount_warn_saturate) from [<b03c56a4>] (kobject_put+0x90/0x98) [<b03c5614>] (kobject_put) from [<b0447b4c>] (put_device+0x20/0x24) r4:b6700140 [<b0447b2c>] (put_device) from [<b07515e8>] (devm_spi_release_controller+0x3c/0x40) [<b07515ac>] (devm_spi_release_controller) from [<b045343c>] (release_nodes+0x84/0xc4) r5:b6700180 r4:b6700100 [<b04533b8>] (release_nodes) from [<b0454160>] (devres_release_all+0x5c/0x60) r8:b1638c54 r7:b117ad94 r6:b1638c10 r5:b117ad94 r4:b163dc10 [<b0454104>] (devres_release_all) from [<b044e41c>] (__device_release_driver+0x144/0x1ec) r5:b117ad94 r4:b163dc10 [<b044e2d8>] (__device_release_driver) from [<b044f70c>] (device_driver_detach+0x84/0xa0) r9:00000000 r8:00000000 r7:b117ad94 r6:b163dc54 r5:b1638c10 r4:b163dc10 [<b044f688>] (device_driver_detach) from [<b044d274>] (unbind_store+0xe4/0xf8) Instead, determine the devm allocation state as a flag on the controller which is guaranteed to be stable during cleanup.
Credit: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Linux Linux kernel | >=4.4.248<4.4.271 | |
| Linux Linux kernel | >=4.9.248<4.9.271 | |
| Linux Linux kernel | >=4.14.212<4.14.233 | |
| Linux Linux kernel | >=4.19.163<4.19.191 | |
| Linux Linux kernel | >=5.4.80<5.4.119 | |
| Linux Linux kernel | >=5.10<5.10.37 | |
| Linux Linux kernel | >=5.11<5.11.21 | |
| Linux Linux kernel | >=5.12<5.12.4 |
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Reference Links
- https://git.kernel.org/stable/c/62bb2c7f2411a0045c24831f11ecacfc35610815
- https://git.kernel.org/stable/c/8bf96425c90f5c1dcf3b7b9df568019a1d4b8a0e
- https://git.kernel.org/stable/c/8e029707f50a82c53172359c686b2536ab54e58c
- https://git.kernel.org/stable/c/28a5529068c51cdf0295ab1e11a99a3a909a03e4
- https://git.kernel.org/stable/c/001c8e83646ad3b847b18f6ac55a54367d917d74
- https://git.kernel.org/stable/c/c7fabe372a9031acd00498bc718ce27c253abfd1
- https://git.kernel.org/stable/c/cee78aa24578edac8cf00513dca618c0acc17cd7
- https://git.kernel.org/stable/c/8735248ebb918d25427965f0db07939ed0473ec6
- https://git.kernel.org/stable/c/794aaf01444d4e765e2b067cba01cc69c1c68ed9
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- version/linux linux kernel/4.4.248
- version/linux linux kernel/4.9.248
- version/linux linux kernel/4.14.212
- version/linux linux kernel/4.19.163
- version/linux linux kernel/5.4.80
- version/linux linux kernel/5.10
- version/linux linux kernel/5.11
- version/linux linux kernel/5.12