Linux Kernel up to 5.15.32/5.16.18/5.17.1 Data Structure dsa_tree_setup_routing_table null pointer dereference

Summaryinfo

A vulnerability categorized as critical has been discovered in Linux Kernel up to 5.15.32/5.16.18/5.17.1. Affected is the function dsa_tree_setup_routing_table of the component Data Structure Handler. Such manipulation leads to null pointer dereference. This vulnerability is traded as CVE-2022-49195. There is no exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 5.15.32/5.16.18/5.17.1. It has been rated as critical. Affected by this issue is the function dsa_tree_setup_routing_table of the component Data Structure Handler. The manipulation with an unknown input leads to a null pointer dereference vulnerability. Using CWE to declare the problem leads to CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. Impacted is availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: net: dsa: fix panic on shutdown if multi-chip tree failed to probe DSA probing is atypical because a tree of devices must probe all at once, so out of N switches which call dsa_tree_setup_routing_table() during probe, for (N - 1) of them, "complete" will return false and they will exit probing early. The Nth switch will set up the whole tree on their behalf. The implication is that for (N - 1) switches, the driver binds to the device successfully, without doing anything. When the driver is bound, the ->shutdown() method may run. But if the Nth switch has failed to initialize the tree, there is nothing to do for the (N - 1) driver instances, since the slave devices have not been created, etc. Moreover, dsa_switch_shutdown() expects that the calling @ds has been in fact initialized, so it jumps at dereferencing the various data structures, which is incorrect. Avoid the ensuing NULL pointer dereferences by simply checking whether the Nth switch has previously set "ds->setup = true" for the switch which is currently shutting down. The entire setup is serialized under dsa2_mutex which we already hold.

The advisory is available at git.kernel.org. This vulnerability is handled as CVE-2022-49195 since 02/26/2025. Technical details are known, but there is no available exploit.

Upgrading to version 5.15.33, 5.16.19 or 5.17.2 eliminates this vulnerability. Applying the patch 95df5cd5a446df6738d2d45872e08594819080e4/b6e668ff43ebd87ccc8a19e5481345c428672295/b864d5350c18bea9369d0bdd9e7eb6f6172cc283/8fd36358ce82382519b50b05f437493e1e00c4a9 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.15.0
• 5.15.1
• 5.15.2
• 5.15.3
• 5.15.4
• 5.15.5
• 5.15.6
• 5.15.7
• 5.15.8
• 5.15.9
• 5.15.10
• 5.15.11
• 5.15.12
• 5.15.13
• 5.15.14
• 5.15.15
• 5.15.16
• 5.15.17
• 5.15.18
• 5.15.19
• 5.15.20
• 5.15.21
• 5.15.22
• 5.15.23
• 5.15.24
• 5.15.25
• 5.15.26
• 5.15.27
• 5.15.28
• 5.15.29
• 5.15.30
• 5.15.31
• 5.15.32
• 5.16.0
• 5.16.1
• 5.16.2
• 5.16.3
• 5.16.4
• 5.16.5
• 5.16.6
• 5.16.7
• 5.16.8
• 5.16.9
• 5.16.10
• 5.16.11
• 5.16.12
• 5.16.13
• 5.16.14
• 5.16.15
• 5.16.16
• 5.16.17
• 5.16.18
• 5.17.0
• 5.17.1

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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