From 78004e9a87f240df03e2f73120d291763c32e0a7 Mon Sep 17 00:00:00 2001 From: Ali Ahmet Memis Date: Fri, 21 Aug 2026 01:45:27 +0000 Subject: openrisc: fix arbitrary kernel memory access via or1k_atomic syscall sys_or1k_atomic() (syscall 244 in the "or1k" ABI) takes two user pointers, v1 and v2, and swaps the words they point to in hand-written assembly. l.lwz r29,0(r4) l.lwz r27,0(r5) l.sw 0(r4),r27 l.sw 0(r5),r29 The pointers are not checked with access_ok(). The four memory accesses also have no exception table entries. A caller passes a kernel address as either pointer, and the syscall reads from and writes to it directly. This gives an unprivileged process a kernel read/write primitive. It overwrites kernel data such as the sys_call_table, gaining code execution in kernel context. Check both pointers before entering the critical section. Add fixups for the four memory accesses so faults on valid but unmapped user addresses return -EFAULT. [shorne@gmail.com: fix comment style] Fixes: 9d02a4283e9c ("OpenRISC: Boot code") Cc: stable@vger.kernel.org Signed-off-by: Ali Ahmet Memis Signed-off-by: Stafford Horne --- Documentation/ABI/testing/debugfs-driver-genwqe | 91 +++++++++++++++++++++++++ 1 file changed, 91 insertions(+) create mode 100644 Documentation/ABI/testing/debugfs-driver-genwqe (limited to 'Documentation/ABI/testing/debugfs-driver-genwqe') diff --git a/Documentation/ABI/testing/debugfs-driver-genwqe b/Documentation/ABI/testing/debugfs-driver-genwqe new file mode 100644 index 000000000..b45b01654 --- /dev/null +++ b/Documentation/ABI/testing/debugfs-driver-genwqe @@ -0,0 +1,91 @@ +What: /sys/kernel/debug/genwqe/genwqe_card/ddcb_info +Date: Oct 2013 +Contact: haver@linux.vnet.ibm.com +Description: DDCB queue dump used for debugging queueing problems. + +What: /sys/kernel/debug/genwqe/genwqe_card/curr_regs +Date: Oct 2013 +Contact: haver@linux.vnet.ibm.com +Description: Dump of the current error registers. + Only available for PF. + +What: /sys/kernel/debug/genwqe/genwqe_card/curr_dbg_uid0 +Date: Oct 2013 +Contact: haver@linux.vnet.ibm.com +Description: Internal chip state of UID0 (unit id 0). + Only available for PF. + +What: /sys/kernel/debug/genwqe/genwqe_card/curr_dbg_uid1 +Date: Oct 2013 +Contact: haver@linux.vnet.ibm.com +Description: Internal chip state of UID1. + Only available for PF. + +What: /sys/kernel/debug/genwqe/genwqe_card/curr_dbg_uid2 +Date: Oct 2013 +Contact: haver@linux.vnet.ibm.com +Description: Internal chip state of UID2. + Only available for PF. + +What: /sys/kernel/debug/genwqe/genwqe_card/prev_regs +Date: Oct 2013 +Contact: haver@linux.vnet.ibm.com +Description: Dump of the error registers before the last reset of + the card occurred. + Only available for PF. + +What: /sys/kernel/debug/genwqe/genwqe_card/prev_dbg_uid0 +Date: Oct 2013 +Contact: haver@linux.vnet.ibm.com +Description: Internal chip state of UID0 before card was reset. + Only available for PF. + +What: /sys/kernel/debug/genwqe/genwqe_card/prev_dbg_uid1 +Date: Oct 2013 +Contact: haver@linux.vnet.ibm.com +Description: Internal chip state of UID1 before card was reset. + Only available for PF. + +What: /sys/kernel/debug/genwqe/genwqe_card/prev_dbg_uid2 +Date: Oct 2013 +Contact: haver@linux.vnet.ibm.com +Description: Internal chip state of UID2 before card was reset. + Only available for PF. + +What: /sys/kernel/debug/genwqe/genwqe_card/info +Date: Oct 2013 +Contact: haver@linux.vnet.ibm.com +Description: Comprehensive summary of bitstream version and software + version. Used bitstream and bitstream clocking information. + +What: /sys/kernel/debug/genwqe/genwqe_card/err_inject +Date: Oct 2013 +Contact: haver@linux.vnet.ibm.com +Description: Possibility to inject error cases to ensure that the drivers + error handling code works well. + +What: /sys/kernel/debug/genwqe/genwqe_card/vf<0..14>_jobtimeout_msec +Date: Oct 2013 +Contact: haver@linux.vnet.ibm.com +Description: Default VF timeout 250ms. Testing might require 1000ms. + Using 0 will use the cards default value (whatever that is). + + The timeout depends on the max number of available cards + in the system and the maximum allowed queue size. + + The driver ensures that the settings are done just before + the VFs get enabled. Changing the timeouts in flight is not + possible. + Only available for PF. + +What: /sys/kernel/debug/genwqe/genwqe_card/jobtimer +Date: Oct 2013 +Contact: haver@linux.vnet.ibm.com +Description: Dump job timeout register values for PF and VFs. + Only available for PF. + +What: /sys/kernel/debug/genwqe/genwqe_card/queue_working_time +Date: Dec 2013 +Contact: haver@linux.vnet.ibm.com +Description: Dump queue working time register values for PF and VFs. + Only available for PF. -- cgit v1.3.1