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CVE-2026-93783

Bluetooth: RFCOMM: validate skb length in rfcomm_recv_frame

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.111, and 1 more
None on Exploit-DB, Metasploit or GitHub

Summary

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: RFCOMM: validate skb length in rfcomm_recv_frame rfcomm_recv_frame() casts skb->data to struct rfcomm_hdr and dereferences hdr->addr and hdr->ctrl without validating skb->len first. A truncated frame with skb->len less than the minimum header size causes an out-of-bounds read of uninitialized memory. Additionally, a zero-length frame causes skb->len-- to underflow to UINT_MAX, making skb_tail_pointer() read far past the buffer. Commit 23882b828c3c ("Bluetooth: RFCOMM: validate skb length in MCC handlers") fixed the same class of missing-length-check bugs in the MCC sub-handlers, but the top-level rfcomm_recv_frame() was left unfixed. KMSAN reports: BUG: KMSAN: uninit-value in rfcomm_run ... Uninit was created at: __alloc_skb+0x474/0xb60 vhci_write+0xe9/0x870 Fix this by rejecting frames smaller than sizeof(struct rfcomm_hdr) + 1 (the minimum frame must have a 3-byte header and a 1-byte FCS).

Timeline

  1. CVE published
  2. Record last updated

Affected versions

  • Linux Linux

    From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in fb40eda15122f6b780228639c1ead6820340ff54; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in 3829af5fab5a22405bf1e7d69068c2ec0fce46ca; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in b161eacd7fa4a2d765724b5504ac6cc388e48f80; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in 30d1d9f3495463f7c026e4c553127f79b486fcd6; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in 67dc3b40fae71b6b11c71e7ff69bac0758818c05; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in bbc310caa2b6bf5fe42896ba27da0fbc12e4ac51; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in b230e5bf501c5edaf2eb0991cb862ac142031d4b

  • Linux Linux

    2.6.12

  • KernelLinux

    From 2.6.12 · fixed in 5.10.271; From 5.11.0 · fixed in 5.15.222; From 5.16.0 · fixed in 6.1.189; From 6.2.0 · fixed in 6.6.158; From 6.7.0 · fixed in 6.12.111; From 6.13.0 · fixed in 6.18.53

References 7

git.kernel.org