CVE-2026-97530scsi: qla2xxx: Fix soft lockup polling continuation IOCB signature

Official description

In the Linux kernel, the following vulnerability has been resolved: scsi: qla2xxx: Fix soft lockup polling continuation IOCB signature qla27xx_copy_multiple_pkt() and qla27xx_copy_fpin_pkt() poll rsp_q->ring_ptr->signature for RESPONSE_PROCESSED (0xDEADDEAD) to decide whether the next continuation IOCB has arrived, spinning on cpu_relax() without advancing the ring or decrementing the entry count while it has not. response_t::signature lives at byte offset 60, but a continuation IOCB (sts_cont_entry_t / struct sts_cont_entry_ext) carries raw FC frame payload at that offset (data[56..59]). A received frame whose payload bytes happen to equal 0xDEADDEAD is therefore misread as "not yet arrived", and the loop spins forever in interrupt/DPC context, causing a CPU soft lockup. The poll is also unnecessary: callers of qla27xx_copy_multiple_pkt() (PT_LS4_UNSOL and the NVMe purls path) already gate on qla_chk_cont_iocb_avail(), which guarantees all entry_count IOCBs are present before copying begins. The sibling helper __qla_copy_purex_to_buffer() already drops the signature poll and relies on the entry_type == STATUS_CONT_TYPE guard instead. Remove the signature busy-wait from both helpers, keeping the entry_type guard, and gate the FPIN path with qla_chk_cont_iocb_avail() so it defers and re-processes on the next interrupt once all continuation IOCBs have arrived, mirroring the ELS_AUTH_ELS and PT_LS4_UNSOL arms. With this the signature field is never read on a continuation IOCB, eliminating the payload-aliasing lockup.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/bded2de273c5b0e50e3e23de937260436cd67df2
• https://git.kernel.org/stable/c/70df7f03499046da0d28a58ec8b237ed5dfbd0a7
• https://git.kernel.org/stable/c/428e244dd4066abd40ca1ec525b7aab9a9db8296
• https://git.kernel.org/stable/c/3e58eb888ebf265af937f636d05997c60d2f197c
• https://git.kernel.org/stable/c/6e6c2ba9022eb8f9b062c81bdc6fd24c7b4c4c16
• https://git.kernel.org/stable/c/6aa722fca9d2aa1f64094101587f8f4a2f83f6aa
• https://git.kernel.org/stable/c/d7e3fa7d06bf7fcaac186d3c4d635caac166d36c