Date: Tue, 21 May 2019 07:42:31 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 238014] Potential NULL pointer dereference in function ata_dev_advinfo and nvme_dev_advinfo Message-ID: <bug-238014-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=238014 Bug ID: 238014 Summary: Potential NULL pointer dereference in function ata_dev_advinfo and nvme_dev_advinfo Product: Base System Version: CURRENT Hardware: Any OS: Any Status: New Severity: Affects Many People Priority: --- Component: kern Assignee: bugs@FreeBSD.org Reporter: yangx92@hotmail.com Created attachment 204502 --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=204502&action=edit Proposed patch There are two NULL pointer vulnerabilities in functions named ata_dev_advinfo (sys/cam/ata/ata_xpt.c) and nvme_dev_advinfo (sys/cam/nvme/nvme_xpt.c). We take function ata_dev_advinfo for example. if (cdai->flags & CDAI_FLAG_STORE) { if (device->physpath != NULL) free(device->physpath, M_CAMXPT); device->physpath_len = cdai->bufsiz; /* Clear existing buffer if zero length */ if (cdai->bufsiz == 0) break; device->physpath = malloc(cdai->bufsiz, M_CAMXPT, M_NOWAIT); if (device->physpath == NULL) { start_ccb->ccb_h.status = CAM_REQ_ABORTED; return; } memcpy(device->physpath, cdai->buf, cdai->bufsiz); if the physical path is being stored and there is a malloc failure (malloc(9) is called with M_NOWAIT), we could wind up in a situation where the device's physpath_len is set to the length the user provided, but the physpath itself is NULL. If another context then comes in to fetch the physical path value, we would wind up trying to memcpy a NULL pointer into the caller's buffer. So, set the physpath_len to 0 when we free the physpath on entry into the store case for the physical path. Reset the length to a non-zero value only after we've successfully malloced a buffer to hold it. The attachment is the proposed patch. -- You are receiving this mail because: You are the assignee for the bug.help
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