Entreprise française de cybersécurité depuis 2004
☎ 03 60 47 09 81 - info@securiteinfo.com
☎ 03 60 47 09 81 - info@securiteinfo.com
In the Linux kernel, the following vulnerability has been resolved:tty: n_gsm: fix possible out-of-bounds in gsm0_receive()Assuming the following:- side A configures the n_gsm in basic option mode- side B sends the header of a basic option mode frame with data length 1- side A switches to advanced option mode- side B sends 2 data bytes which exceeds gsm->len Reason: gsm->len is not used in advanced option mode.- side A switches to basic option mode- side B keeps sending until gsm0_receive() writes past gsm->buf Reason: Neither gsm->state nor gsm->len have been reset after reconfiguration.Fix this by changing gsm->count to gsm->len comparison from equal to lessthan. Also add upper limit checks against the constant MAX_MRU ingsm0_receive() and gsm1_receive() to harden against memory corruption ofgsm->len and gsm->mru.All other checks remain as we still need to limit the data according to theuser configuration and actual payload size.
No PoCs from references.
- https://github.com/xairy/linux-kernel-exploitation