CVE-2026-90088

Bluetooth: RFCOMM: Validate MTU in rfcomm_apply_pn() to prevent infinite loop

State: Published
Severity: Not scored
Published: Sep 17, 2026
Updated: Oct 19, 2026
Reserved: Sep 11, 2026

Description

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: RFCOMM: Validate MTU in rfcomm_apply_pn() to prevent infinite loop

rfcomm_apply_pn() accepts the MTU value from a remote PN (Parameter Negotiation) frame without checking for zero. When the remote peer sends an MTU of zero, d->mtu is set to 0. This causes the sendmsg path to enter an infinite loop when fragmenting data, as each fragment has size == min_t(size_t, len, 0) == 0, so the remaining length never decreases. The infinite allocation of zero-length skbs exhausts all system memory.

Fix by clamping d->mtu to RFCOMM_DEFAULT_MTU when the negotiated value is zero, consistent with the initial value assigned in rfcomm_dlc_alloc().

Scores

The record has no CVSS score.

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before e7c0aa45ae6c5a338661b23812bfcdef50bf3e96Affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before cbc2962da99b6b89345267d3aa74b4b573340548Affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 9b2e5f1928c99224345a9ed8c5dae5fc74964d6dAffected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before fc4851ff8dfb505e9a19efcc286712132bbd178dAffected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before f561e44261344adadf9d6a6dff31e3af9776d5c6Affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before aeee917a4878af95f0c63e18c5f22eaf6299c7b8Affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 3988cbb1be501dbff909a2ee024670e3c955a66dAffected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 44c98fd082eafd49d55a8a4077ff488175b2fe24Affected
LinuxLinux	2.6.12Affected before 2.6.12Not affected 5.10.270 through 5.10.Not affected 5.15.221 through 5.15.Not affected 6.1.188 through 6.1.Not affected 6.6.157 through 6.6.Not affected 6.12.110 through 6.12.Not affected 6.18.52 through 6.18.Not affected 7.2.6 through 7.2.*Not affected 7.3 and laterNot affected

Product

Versions

LinuxLinux

1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before e7c0aa45ae6c5a338661b23812bfcdef50bf3e96Affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before cbc2962da99b6b89345267d3aa74b4b573340548Affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 9b2e5f1928c99224345a9ed8c5dae5fc74964d6dAffected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before fc4851ff8dfb505e9a19efcc286712132bbd178dAffected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before f561e44261344adadf9d6a6dff31e3af9776d5c6Affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before aeee917a4878af95f0c63e18c5f22eaf6299c7b8Affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 3988cbb1be501dbff909a2ee024670e3c955a66dAffected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 44c98fd082eafd49d55a8a4077ff488175b2fe24Affected

LinuxLinux

2.6.12Affected
before 2.6.12Not affected
5.10.270 through 5.10.*Not affected
5.15.221 through 5.15.*Not affected
6.1.188 through 6.1.*Not affected
6.6.157 through 6.6.*Not affected
6.12.110 through 6.12.*Not affected
6.18.52 through 6.18.*Not affected
7.2.6 through 7.2.*Not affected
7.3 and laterNot affected

References

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.