UBUNTU-CVE-2021-46959
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.
02 / AFFECTED SOFTWARE
Affected packages
50 explicit affected versions
6 explicit affected versions
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1 explicit affected versions
7 explicit affected versions
67 explicit affected versions
27 explicit affected versions
47 explicit affected versions
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35 explicit affected versions
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13 explicit affected versions
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107 explicit affected versions
1 explicit affected versions
21 explicit affected versions
16 explicit affected versions
10 explicit affected versions
7 explicit affected versions
12 explicit affected versions
12 explicit affected versions
1 explicit affected versions
7 explicit affected versions
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29 explicit affected versions
37 explicit affected versions
12 explicit affected versions
29 explicit affected versions
106 explicit affected versions
22 explicit affected versions
174 explicit affected versions
37 explicit affected versions
10 explicit affected versions
26 explicit affected versions
13 explicit affected versions
29 explicit affected versions
13 explicit affected versions
61 explicit affected versions
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23 explicit affected versions
10 explicit affected versions
46 explicit affected versions
11 explicit affected versions
12 explicit affected versions
69 explicit affected versions
7 explicit affected versions
12 explicit affected versions
29 explicit affected versions
151 explicit affected versions
25 explicit affected versions
10 explicit affected versions
26 explicit affected versions
13 explicit affected versions
16 explicit affected versions
3 explicit affected versions
51 explicit affected versions
23 explicit affected versions
12 explicit affected versions
27 explicit affected versions
1 explicit affected versions
26 explicit affected versions
8 explicit affected versions
5 explicit affected versions
19 explicit affected versions
8 explicit affected versions
20 explicit affected versions
10 explicit affected versions
13 explicit affected versions
7 explicit affected versions
23 explicit affected versions
10 explicit affected versions
12 explicit affected versions
18 explicit affected versions
44 explicit affected versions
16 explicit affected versions
3 explicit affected versions
13 explicit affected versions
26 explicit affected versions
37 explicit affected versions
38 explicit affected versions
9 explicit affected versions
11 explicit affected versions
19 explicit affected versions
7 explicit affected versions
84 explicit affected versions
3 explicit affected versions
77 explicit affected versions
54 explicit affected versions
4 explicit affected versions
45 explicit affected versions
19 explicit affected versions
43 explicit affected versions
130 explicit affected versions
92 explicit affected versions
10 explicit affected versions
8 explicit affected versions
14 explicit affected versions
22 explicit affected versions
4 explicit affected versions
9 explicit affected versions
1 explicit affected versions
1 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
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.
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/794aaf01444d4e765e2b067cba01cc69c1c68ed9
- https://ubuntu.com/security/CVE-2021-46959
- https://ubuntu.com/security/notices/USN-7506-1
- https://ubuntu.com/security/notices/USN-7506-2
- https://ubuntu.com/security/notices/USN-7506-3
- https://ubuntu.com/security/notices/USN-7506-4
- https://www.cve.org/CVERecord?id=CVE-2021-46959