CVE-2023-52995

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

riscv/kprobe: Fix instruction simulation of JALR

Set kprobe at jalr 1140(ra) of vfs_write results in the following crash:

[ 32.092235] Unable to handle kernel access to user memory without uaccess routines at virtual address 00aaaaaad77b1170 [ 32.093115] Oops [#1] [ 32.093251] Modules linked in: [ 32.093626] CPU: 0 PID: 135 Comm: ftracetest Not tainted 6.2.0-rc2-00013-gb0aa5e5df0cb-dirty #16 [ 32.093985] Hardware name: riscv-virtio,qemu (DT) [ 32.094280] epc : ksys_read+0x88/0xd6 [ 32.094855] ra : ksys_read+0xc0/0xd6 [ 32.095016] epc : ffffffff801cda80 ra : ffffffff801cdab8 sp : ff20000000d7bdc0 [ 32.095227] gp : ffffffff80f14000 tp : ff60000080f9cb40 t0 : ffffffff80f13e80 [ 32.095500] t1 : ffffffff8000c29c t2 : ffffffff800dbc54 s0 : ff20000000d7be60 [ 32.095716] s1 : 0000000000000000 a0 : ffffffff805a64ae a1 : ffffffff80a83708 [ 32.095921] a2 : ffffffff80f160a0 a3 : 0000000000000000 a4 : f229b0afdb165300 [ 32.096171] a5 : f229b0afdb165300 a6 : ffffffff80eeebd0 a7 : 00000000000003ff [ 32.096411] s2 : ff6000007ff76800 s3 : fffffffffffffff7 s4 : 00aaaaaad77b1170 [ 32.096638] s5 : ffffffff80f160a0 s6 : ff6000007ff76800 s7 : 0000000000000030 [ 32.096865] s8 : 00ffffffc3d97be0 s9 : 0000000000000007 s10: 00aaaaaad77c9410 [ 32.097092] s11: 0000000000000000 t3 : ffffffff80f13e48 t4 : ffffffff8000c29c [ 32.097317] t5 : ffffffff8000c29c t6 : ffffffff800dbc54 [ 32.097505] status: 0000000200000120 badaddr: 00aaaaaad77b1170 cause: 000000000000000d [ 32.098011] [] ksys_write+0x6c/0xd6 [ 32.098222] [] sys_write+0x2a/0x38 [ 32.098405] [] ret_from_syscall+0x0/0x2

Since the rs1 and rd might be the same one, such as jalr 1140(ra), hence it requires obtaining the target address from rs1 followed by updating rd.

[Palmer: Pick Guos cleanup]

Affected Software

References

• https://git.kernel.org/stable/c/614471b7f7cd28a2c96ab9c90b37471c82258ffb
• https://git.kernel.org/stable/c/ca0254998be4d74cf6add70ccfab0d2dbd362a10
• https://git.kernel.org/stable/c/f4c8fc775fcbc9e9047b22671c55ca18f9a127d4