CVE-2022-49808: In the Linux kernel, the following vulnerability has been resolved: net: dsa: don't leak tagger-owned storage on switch driver unbind In the initial commit…

PriorityP421medium5.5CVSS 3.1

AVLACLPRLUINSUCNINAH

EPSS

0.16%

5.6th percentile

In the Linux kernel, the following vulnerability has been resolved: net: dsa: don't leak tagger-owned storage on switch driver unbind In the initial commit dc452a471dba ("net: dsa: introduce tagger-owned storage for private and shared data"), we had a call to tag_ops->disconnect(dst) issued from dsa_tree_free(), which is called at tree teardown time. There were problems with connecting to a switch tree as a whole, so this got reworked to connecting to individual switches within the tree. In this process, tag_ops->disconnect(ds) was made to be called only from switch.c (cross-chip notifiers emitted as a result of dynamic tag proto changes), but the normal driver teardown code path wasn't replaced with anything. Solve this problem by adding a function that does the opposite of dsa_switch_setup_tag_protocol(), which is called from the equivalent spot in dsa_switch_teardown(). The positioning here also ensures that we won't have any use-after-free in tagging protocol (*rcv) ops, since the teardown sequence is as follows: dsa_tree_teardown -> dsa_tree_teardown_master -> dsa_master_teardown -> unsets master->dsa_ptr, making no further packets match the ETH_P_XDSA packet type handler -> dsa_tree_teardown_ports -> dsa_port_teardown -> dsa_slave_destroy -> unregisters DSA net devices, there is even a synchronize_net() in unregister_netdevice_many() -> dsa_tree_teardown_switches -> dsa_switch_teardown -> dsa_switch_teardown_tag_protocol -> finally frees the tagger-owned storage

Affected

9 ranges

Vendor	Product	Version range	Fixed in
debian	linux	< linux 6.0.10-1 (bookworm)	linux 6.0.10-1 (bookworm)
linux	linux	—	—
linux	linux	>= 7f2973149c22e7a6fee4c0c9fa6b8e4108e9c208 < 5809fb03942dbac25144db5bebea84fa003ecaca	5809fb03942dbac25144db5bebea84fa003ecaca
linux	linux	>= 7f2973149c22e7a6fee4c0c9fa6b8e4108e9c208 < 4e0c19fcb8b5323716140fa82b79aa9f60e60407	4e0c19fcb8b5323716140fa82b79aa9f60e60407
linux	linux_kernel	—	—
linux	linux_kernel	>= 0 < 6.0.10-1	6.0.10-1
linux	linux_kernel	>= 0 < 6.0.10-1	6.0.10-1
linux	linux_kernel	>= 0 < 6.0.10-1	6.0.10-1
linux	linux_kernel	>= 5.17 < 6.0.10	6.0.10

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

osv5.5MEDIUM

vendor_debian5.5MEDIUM

vendor_redhat5.5MEDIUM

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