Jisheng Zhang a8616d2dc1 riscv: vdso: fix NULL deference in vdso_join_timens() when vfork ... Testing tools/testing/selftests/timens/vfork_exec.c got below kernel log: [ 6.838454] Unable to handle kernel access to user memory without uaccess routines at virtual address 0000000000000020 [ 6.842255] Oops [#1] [ 6.842871] Modules linked in: [ 6.844249] CPU: 1 PID: 64 Comm: vfork_exec Not tainted 6.0.0-rc3-rt15+ #8 [ 6.845861] Hardware name: riscv-virtio,qemu (DT) [ 6.848009] epc : vdso_join_timens+0xd2/0x110 [ 6.850097] ra : vdso_join_timens+0xd2/0x110 [ 6.851164] epc : ffffffff8000635c ra : ffffffff8000635c sp : ff6000000181fbf0 [ 6.852562] gp : ffffffff80cff648 tp : ff60000000fdb700 t0 : 3030303030303030 [ 6.853852] t1 : 0000000000000030 t2 : 3030303030303030 s0 : ff6000000181fc40 [ 6.854984] s1 : ff60000001e6c000 a0 : 0000000000000010 a1 : ffffffff8005654c [ 6.856221] a2 : 00000000ffffefff a3 : 0000000000000000 a4 : 0000000000000000 [ 6.858114] a5 : 0000000000000000 a6 : 0000000000000008 a7 : 0000000000000038 [ 6.859484] s2 : ff60000001e6c068 s3 : ff6000000108abb0 s4 : 0000000000000000 [ 6.860751] s5 : 0000000000001000 s6 : ffffffff8089dc40 s7 : ffffffff8089dc38 [ 6.862029] s8 : ffffffff8089dc30 s9 : ff60000000fdbe38 s10: 000000000000005e [ 6.863304] s11: ffffffff80cc3510 t3 : ffffffff80d1112f t4 : ffffffff80d1112f [ 6.864565] t5 : ffffffff80d11130 t6 : ff6000000181fa00 [ 6.865561] status: 0000000000000120 badaddr: 0000000000000020 cause: 000000000000000d [ 6.868046] [<ffffffff8008dc94>] timens_commit+0x38/0x11a [ 6.869089] [<ffffffff8008dde8>] timens_on_fork+0x72/0xb4 [ 6.870055] [<ffffffff80190096>] begin_new_exec+0x3c6/0x9f0 [ 6.871231] [<ffffffff801d826c>] load_elf_binary+0x628/0x1214 [ 6.872304] [<ffffffff8018ee7a>] bprm_execve+0x1f2/0x4e4 [ 6.873243] [<ffffffff8018f90c>] do_execveat_common+0x16e/0x1ee [ 6.874258] [<ffffffff8018f9c8>] sys_execve+0x3c/0x48 [ 6.875162] [<ffffffff80003556>] ret_from_syscall+0x0/0x2 [ 6.877484] ---[ end trace 0000000000000000 ]--- This is because the mm->context.vdso_info is NULL in vfork case. From another side, mm->context.vdso_info either points to vdso info for RV64 or vdso info for compat, there's no need to bloat riscv's mm_context_t, we can handle the difference when setup the additional page for vdso. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Suggested-by: Palmer Dabbelt <palmer@rivosinc.com> Fixes: 3092eb4563 ("riscv: compat: vdso: Add setup additional pages implementation") Link: https://lore.kernel.org/r/20220924070737.3048-1-jszhang@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>		2022-10-13 11:16:52 -07:00
..
boot	Microchip RISC-V devicetrees for v6.1	2022-10-12 14:59:54 -07:00
configs	riscv: enable CD-ROM file systems in defconfig	2022-08-25 17:01:09 -07:00
errata	Merge patch series "Some style cleanups for recent extension additions"	2022-10-13 08:46:31 -07:00
include	riscv: vdso: fix NULL deference in vdso_join_timens() when vfork	2022-10-13 11:16:52 -07:00
kernel	riscv: vdso: fix NULL deference in vdso_join_timens() when vfork	2022-10-13 11:16:52 -07:00
kvm	The first batch of KVM patches, mostly covering x86, which I	2022-10-09 09:39:55 -07:00
lib	riscv: lib: uaccess: fix CSR_STATUS SR_SUM bit	2022-08-10 14:06:31 -07:00
mm	RISC-V Fixes for 6.0-rc7	2022-09-23 08:51:05 -07:00
net	bpf, riscv: Support riscv jit to provide bpf_line_info	2022-06-02 16:26:01 -07:00
purgatory	riscv/purgatory: Omit use of bin2c	2022-08-11 09:32:34 -07:00
Kbuild	riscv: move errata/ and kvm/ builds to arch/riscv/Kbuild	2022-06-01 22:26:32 -07:00
Kconfig	RISC-V Patches for the 6.1 Merge Window, Part 1	2022-10-09 13:24:01 -07:00
Kconfig.debug	RISC-V: Remove EARLY_PRINTK support	2018-12-17 10:23:46 -08:00
Kconfig.erratas	riscv: make t-head erratas depend on MMU	2022-09-17 01:48:22 -07:00
Kconfig.socs	riscv: Kconfig: Style cleanups	2022-06-30 19:26:16 -07:00
Makefile	riscv: Pass -mno-relax only on lld < 15.0.0	2022-10-13 08:24:34 -07:00