Affected: Linux

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

scsi: hisi_sas: Create all dump files during debugfs initialization

For the current debugfs of hisi_sas, after user triggers dump, the driver allocate memory space to save the register information and create debugfs files to display the saved information. In this process, the debugfs files created after each dump.

Therefore, when the dump is triggered while the driver is unbind, the following hang occurs:

[67840.853907] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000a0 [67840.862947] Mem abort info: [67840.865855] ESR = 0x0000000096000004 [67840.869713] EC = 0x25: DABT (current EL), IL = 32 bits [67840.875125] SET = 0, FnV = 0 [67840.878291] EA = 0, S1PTW = 0 [67840.881545] FSC = 0x04: level 0 translation fault [67840.886528] Data abort info: [67840.889524] ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 [67840.895117] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [67840.900284] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [67840.905709] user pgtable: 4k pages, 48-bit VAs, pgdp=0000002803a1f000 [67840.912263] [00000000000000a0] pgd=0000000000000000, p4d=0000000000000000 [67840.919177] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP [67840.996435] pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [67841.003628] pc : down_write+0x30/0x98 [67841.007546] lr : start_creating.part.0+0x60/0x198 [67841.012495] sp : ffff8000b979ba20 [67841.016046] x29:…