diff options
| -rw-r--r-- | kernel/events/uprobes.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index e51ec844c87c..5dc2f46f38c0 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -861,10 +861,6 @@ static int prepare_uprobe(struct uprobe *uprobe, struct file *file, if (ret) goto out; - /* uprobe_write_opcode() assumes we don't cross page boundary */ - BUG_ON((uprobe->offset & ~PAGE_MASK) + - UPROBE_SWBP_INSN_SIZE > PAGE_SIZE); - smp_wmb(); /* pairs with the smp_rmb() in handle_swbp() */ set_bit(UPROBE_COPY_INSN, &uprobe->flags); @@ -1160,6 +1156,15 @@ static int __uprobe_register(struct inode *inode, loff_t offset, if (offset > i_size_read(inode)) return -EINVAL; + /* + * This ensures that copy_from_page(), copy_to_page() and + * __update_ref_ctr() can't cross page boundary. + */ + if (!IS_ALIGNED(offset, UPROBE_SWBP_INSN_SIZE)) + return -EINVAL; + if (!IS_ALIGNED(ref_ctr_offset, sizeof(short))) + return -EINVAL; + retry: uprobe = alloc_uprobe(inode, offset, ref_ctr_offset); if (!uprobe) @@ -2008,6 +2013,9 @@ static int is_trap_at_addr(struct mm_struct *mm, unsigned long vaddr) uprobe_opcode_t opcode; int result; + if (WARN_ON_ONCE(!IS_ALIGNED(vaddr, UPROBE_SWBP_INSN_SIZE))) + return -EINVAL; + pagefault_disable(); result = __get_user(opcode, (uprobe_opcode_t __user *)vaddr); pagefault_enable(); |