Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix ERTM re-init and zero pdu_len infinite loop l2cap_config_req() processes CONFIG_REQ for channels in BT_CONNECTED state to support L2CAP reconfiguration (e.g. MTU changes). However, since both CONF_INPUT_DONE and CONF_OUTPUT_DONE are already set from the initial configuration, the reconfiguration path falls through to l2cap_ertm_init(), which re-initializes tx_q, srej_q, srej_list, and retrans_list without freeing the previous allocations and sets chan->sdu to NULL without freeing the existing skb. This leaks all previously allocated ERTM resources. Additionally, l2cap_parse_conf_req() does not validate the minimum value of remote_mps derived from the RFC max_pdu_size option. A zero value propagates to l2cap_segment_sdu() where pdu_len becomes zero, causing the while loop to never terminate since len is never decremented, exhausting all available memory. Fix the double-init by skipping l2cap_ertm_init() and l2cap_chan_ready() when the channel is already in BT_CONNECTED state, while still allowing the reconfiguration parameters to be updated through l2cap_parse_conf_req(). Also add a pdu_len zero check in l2cap_segment_sdu() as a safeguard.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 96298f640104e4cd9a913a6e50b0b981829b94ff before 9760b83cfd24b38caee663f429011a0dd6064fa9; affected 96298f640104e4cd9a913a6e50b0b981829b94ff before de37e2655b7abc3f59254c6b72256840f39fc6d5; affected 96298f640104e4cd9a913a6e50b0b981829b94ff before e7aab23b7df89a3d754a5f0a7d2237548b328bd0; affected 96298f640104e4cd9a913a6e50b0b981829b94ff before 52667c859fe33f70c2e711cb81bbd505d5eb8e75; affected 96298f640104e4cd9a913a6e50b0b981829b94ff before 9a21a631ee034b1573dce14b572a24943dbfd7ae; affected 96298f640104e4cd9a913a6e50b0b981829b94ff before 900e4db5385ec2cacd372345a80ab9c8e105b3a3; affected 96298f640104e4cd9a913a6e50b0b981829b94ff before 042e2cd4bb11e5313b19b87593616524949e4c52; affected 96298f640104e4cd9a913a6e50b0b981829b94ff before 25f420a0d4cfd61d3d23ec4b9c56d9f443d91377; affected 4ad03ff6f680681c5f78254e37c4c856fa953629; affected b7d0ca715c1008acd2fc018f02a56fed88f78b75; affected 799263eb37a4f7f6d39334046929c3bc92452a7f; affected 8828622fb9b4201eeb0870587052e3d834cfaf61; affected b432ea85ab8472763870dd0f2c186130dd36d68c; affected 4.4.238 before 4.5; affected 4.9.238 before 4.10; affected 4.14.200 before 4.15; affected 4.19.149 before 4.20; affected 5.4.69 before 5.5 |
| Linux / Linux | affected 5.7; unaffected 0 before 5.7; unaffected 5.10.253 through 5.10.*; unaffected 5.15.203 through 5.15.*; unaffected 6.1.168 through 6.1.*; unaffected 6.6.131 through 6.6.*; unaffected 6.12.80 through 6.12.*; unaffected 6.18.21 through 6.18.*; unaffected 6.19.11 through 6.19.*; unaffected 7.0 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/9760b83cfd24b38caee663f429011a0dd6064fa9
- https://git.kernel.org/stable/c/de37e2655b7abc3f59254c6b72256840f39fc6d5
- https://git.kernel.org/stable/c/e7aab23b7df89a3d754a5f0a7d2237548b328bd0
- https://git.kernel.org/stable/c/52667c859fe33f70c2e711cb81bbd505d5eb8e75
- https://git.kernel.org/stable/c/9a21a631ee034b1573dce14b572a24943dbfd7ae
- https://git.kernel.org/stable/c/900e4db5385ec2cacd372345a80ab9c8e105b3a3
- https://git.kernel.org/stable/c/042e2cd4bb11e5313b19b87593616524949e4c52
- https://git.kernel.org/stable/c/25f420a0d4cfd61d3d23ec4b9c56d9f443d91377