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 --- fs/ubifs/misc.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 69 insertions(+) create mode 100644 fs/ubifs/misc.c (limited to 'fs/ubifs/misc.c') diff --git a/fs/ubifs/misc.c b/fs/ubifs/misc.c new file mode 100644 index 000000000..cd23de0f2 --- /dev/null +++ b/fs/ubifs/misc.c @@ -0,0 +1,69 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include "ubifs.h" + +/* Normal UBIFS messages */ +void ubifs_msg(const struct ubifs_info *c, const char *fmt, ...) +{ + struct va_format vaf; + va_list args; + + va_start(args, fmt); + + vaf.fmt = fmt; + vaf.va = &args; + + pr_notice("UBIFS (ubi%d:%d): %pV\n", + c->vi.ubi_num, c->vi.vol_id, &vaf); + + va_end(args); +} \ + +/* UBIFS error messages */ +void ubifs_err(const struct ubifs_info *c, const char *fmt, ...) +{ + struct va_format vaf; + va_list args; + + va_start(args, fmt); + + vaf.fmt = fmt; + vaf.va = &args; + + pr_err("UBIFS error (ubi%d:%d pid %d): %ps: %pV\n", + c->vi.ubi_num, c->vi.vol_id, current->pid, + __builtin_return_address(0), + &vaf); + + va_end(args); +} \ + +/* UBIFS warning messages */ +void ubifs_warn(const struct ubifs_info *c, const char *fmt, ...) +{ + struct va_format vaf; + va_list args; + + va_start(args, fmt); + + vaf.fmt = fmt; + vaf.va = &args; + + pr_warn("UBIFS warning (ubi%d:%d pid %d): %ps: %pV\n", + c->vi.ubi_num, c->vi.vol_id, current->pid, + __builtin_return_address(0), + &vaf); + + va_end(args); +} + +static char *assert_names[] = { + [ASSACT_REPORT] = "report", + [ASSACT_RO] = "read-only", + [ASSACT_PANIC] = "panic", +}; + +const char *ubifs_assert_action_name(struct ubifs_info *c) +{ + return assert_names[c->assert_action]; +} -- cgit v1.3.1