title: spi: Fix use-after-free with devm_spi_alloc_*
description: 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.
affected:
{
product: Linux
vendor: Linux
defaultStatus: unaffected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: a4add022c155, lessThan: 62bb2c7f2411, status: affected, versionType: git
version: 0870525cf94b, lessThan: 8bf96425c90f, status: affected, versionType: git
version: 8c45a1c6c951, lessThan: 8e029707f50a, status: affected, versionType: git
version: 234b432c7b61, lessThan: 28a5529068c5, status: affected, versionType: git
version: 3e04a4976add, lessThan: 001c8e83646a, status: affected, versionType: git
version: 5e844cc37a5c, lessThan: c7fabe372a90, status: affected, versionType: git
version: 5e844cc37a5c, lessThan: cee78aa24578, status: affected, versionType: git
version: 5e844cc37a5c, lessThan: 8735248ebb91, status: affected, versionType: git
version: 5e844cc37a5c, lessThan: 794aaf01444d, status: affected, versionType: git
}
{
product: Linux
vendor: Linux
defaultStatus: affected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: 5.10, status: affected
version: 0, lessThan: 5.10, status: unaffected, versionType: custom
version: 4.4.271, lessThanOrEqual: 4.4.*, status: unaffected, versionType: custom
version: 4.9.271, lessThanOrEqual: 4.9.*, status: unaffected, versionType: custom
version: 4.14.233, lessThanOrEqual: 4.14.*, status: unaffected, versionType: custom
version: 4.19.191, lessThanOrEqual: 4.19.*, status: unaffected, versionType: custom
version: 5.4.119, lessThanOrEqual: 5.4.*, status: unaffected, versionType: custom
version: 5.10.37, lessThanOrEqual: 5.10.*, status: unaffected, versionType: custom
version: 5.11.21, lessThanOrEqual: 5.11.*, status: unaffected, versionType: custom
version: 5.12.4, lessThanOrEqual: 5.12.*, status: unaffected, versionType: custom
version: 5.13, lessThanOrEqual: *, status: unaffected, versionType: original_commit_for_fix
}
