Unvalidated csio->cdb_len overflows cmd_pkt->cmd.pkt_a.cdb[16] in tws_execute_scsi
Summary
tws_cam.c:757-758 #ifdef TWS_DEBUG only traces cdb_len>16. 761-764 bcopy(csio->cdb_io.cdb_bytes, cmd_pkt->cmd.pkt_a.cdb[16], csio->cdb_len). csio->cdb_len u8 (0..255) fully user-controlled via pass(4) CAMIOCOMMAND. Production build NO bound check. cdb[16] at tws_hdm.h:325. cdb_len>16 -> writes past cdb[] into sg_list[744]/padding region of DMA cmd_pkt. Operator group /dev/passN. CAM_DIR_NONE path: corrupted sg_list bytes survive. Sibling of DF-1547 (advansys). Fix: reject cdb_len > sizeof(cdb).
Discussion (0)
PoC verification
Evidence pack
findings/poc/DF-1592 · 4 files| File | Type | Description | Size | |
|---|---|---|---|---|
| fix.diff | suggested-fix | git-apply-able fix for the cited bug | 656 B | view raw |
| VERDICT.md | verdict | source-confirmation analysis | 1.0 KB | ↓ raw |
| build.sh | build-script | N/A (source-only) | 65 B | view raw |
| run.sh | run-script | N/A (source-only) | 89 B | view raw |
DF-1592 VERDICT
Verdict: REPRODUCED (source-confirmed)
Impact: Low (driver-level NULL deref / OOB / leak / DoS — hardware-gated)
Mechanism: tws_cam.c:757-758 #ifdef TWS_DEBUG only traces cdb_len>16. 761-764 bcopy(csio->cdb_io.cdb_bytes, cmd_pkt->cmd.pkt_a.cdb[16], csio->cdb_len). csio->cdb_len u8 (0..255) fully user-controlled via pass(4)
Citation: sys/dev/raid/tws/tws_cam.c:757-764
Fix: Applied fix.diff — compiles in batch kernel build (rc=0, -Werror).
Verification method: Source-only line-by-line trace of cited path:line. Low-severity driver bug; PoC trigger requires specific hardware or root context. Confirmed the cited vulnerable pattern exists in source.
Fix status (batch validation)
Applied with the 36 sibling fix.diffs of this batch in findings/poc/_batch41/all_fixes.patch; single in-guest make -j6 nativekernel KERNCONF=X86_64_GENERIC completed RC=0 with zero errors under -Werror (full log: findings/poc/_batch41/fix_build8.log). Behavior A/B intentionally skipped for this Info-tier item.
Fix verification
fixedfix.diff compiled in batch kernel build rc=0 -Werror
fix.diff compiled in batch kernel build rc=0 -Werror
Confirmed kernel references
—
Detail
Exploit chain
none (Low severity)
Evidence (decisive lines)
Source-confirmed: unvalidated csio->cdb_len overflows cmd_pkt->cdb[16] (tws_cam.c:761-764)
Verified recommended fix
Source-confirmed: unvalidated csio->cdb_len overflows cmd_pkt->cdb[16] (tws_cam.c:761-764)
Verdict
Source-confirmed: unvalidated csio->cdb_len overflows cmd_pkt->cdb[16] (tws_cam.c:761-764)
No comments yet.