Affected: Linux

In the Linux kernel, the following vulnerability has been resolved:

scsi: hisi_sas: Fix NULL pointer exception during user_scan()

user_scan() invokes updated sas_user_scan() for channel 0, and if successful, iteratively scans remaining channels (1 to shost->max_channel) via scsi_scan_host_selected() in commit 37c4e72b0651 ("scsi: Fix sas_user_scan() to handle wildcard and multi-channel scans"). However, hisi_sas supports only one channel, and the current value of max_channel is 1. sas_user_scan() for channel 1 will trigger the following NULL pointer exception:

[ 441.554662] Unable to handle kernel NULL pointer dereference at virtual address 00000000000008b0 [ 441.554699] Mem abort info: [ 441.554710] ESR = 0x0000000096000004 [ 441.554718] EC = 0x25: DABT (current EL), IL = 32 bits [ 441.554723] SET = 0, FnV = 0 [ 441.554726] EA = 0, S1PTW = 0 [ 441.554730] FSC = 0x04: level 0 translation fault [ 441.554735] Data abort info: [ 441.554737] ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 [ 441.554742] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 441.554747] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 441.554752] user pgtable: 4k pages, 48-bit VAs, pgdp=00000828377a6000 [ 441.554757] [00000000000008b0] pgd=0000000000000000, p4d=0000000000000000 [ 441.554769] Internal error: Oops: 0000000096000004 [#1] SMP [ 441.629589] Modules linked in: arm_spe_pmu arm_smmuv3_pmu tpm_tis_spi hisi_uncore_sllc_pmu hisi_uncore_pa_pmu hisi_uncore_l3c_pmu hisi_uncore_hh…