Affected: Linux

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

hwmon: (gpio-fan) Fix array out of bounds access

The driver does not check if the cooling state passed to gpio_fan_set_cur_state() exceeds the maximum cooling state as stored in fan_data->num_speeds. Since the cooling state is later used as an array index in set_fan_speed(), an array out of bounds access can occur. This can be exploited by setting the state of the thermal cooling device to arbitrary values, causing for example a kernel oops when unavailable memory is accessed this way.

Example kernel oops: [ 807.987276] Unable to handle kernel paging request at virtual address ffffff80d0588064 [ 807.987369] Mem abort info: [ 807.987398] ESR = 0x96000005 [ 807.987428] EC = 0x25: DABT (current EL), IL = 32 bits [ 807.987477] SET = 0, FnV = 0 [ 807.987507] EA = 0, S1PTW = 0 [ 807.987536] FSC = 0x05: level 1 translation fault [ 807.987570] Data abort info: [ 807.987763] ISV = 0, ISS = 0x00000005 [ 807.987801] CM = 0, WnR = 0 [ 807.987832] swapper pgtable: 4k pages, 39-bit VAs, pgdp=0000000001165000 [ 807.987872] [ffffff80d0588064] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000 [ 807.987961] Internal error: Oops: 96000005 [#1] PREEMPT SMP [ 807.987992] Modules linked in: cmac algif_hash aes_arm64 algif_skcipher af_alg bnep hci_uart btbcm bluetooth ecdh_generic ecc 8021q garp stp llc snd_soc_hdmi_codec brcmfmac vc4 brcmutil cec drm_kms_helper snd_soc_core cfg80211 s…