dtrace: ensure memory allocation results are checked throughout the code

Signed-off-by: Kris Van Hees <kris.van.hees@oracle.com>

diff --git a/include/linux/dtrace_os.h b/include/linux/dtrace_os.h
index 3d2a71c6ae747f5419369c3ff789179d1fe8c0b7..d8e564275cac47b33f65199cdc1b98afa04afae1 100644 (file)
--- a/include/linux/dtrace_os.h
+++ b/include/linux/dtrace_os.h
@@ -29,7 +29,7 @@ extern void dtrace_os_exit(void);
 extern void dtrace_enable(void);
 extern void dtrace_disable(void);
 
-extern void dtrace_invop_add(uint8_t (*func)(struct pt_regs *));
+extern int dtrace_invop_add(uint8_t (*func)(struct pt_regs *));
 extern void dtrace_invop_remove(uint8_t (*func)(struct pt_regs *));
 
 extern void dtrace_invop_enable(uint8_t *);

diff --git a/kernel/dtrace/dtrace_os.c b/kernel/dtrace/dtrace_os.c
index 0ceadf6f15e4e7c0dd7ec3ed073ed6d9420bce6a..1f5d923db9887a4a495f3f4264df751ef4f90b65 100644 (file)
--- a/kernel/dtrace/dtrace_os.c
+++ b/kernel/dtrace/dtrace_os.c
@@ -81,11 +81,8 @@ dtrace_psinfo_t *dtrace_psinfo_alloc(struct task_struct *task)
        struct mm_struct        *mm;
 
        psinfo = kzalloc(sizeof(dtrace_psinfo_t), GFP_KERNEL);
-       if (psinfo == NULL) {
-               pr_warning("%s: cannot allocate DTrace psinfo structure\n",
-                          __func__);
-               return NULL;
-       }
+       if (psinfo == NULL)
+               goto fail;
 
        mm = get_task_mm(task);
        if (mm) {
@@ -125,6 +122,8 @@ dtrace_psinfo_t *dtrace_psinfo_alloc(struct task_struct *task)
                }
 
                psinfo->argv = vmalloc((psinfo->argc + 1) * sizeof(char *));
+               if (psinfo->argv == NULL)
+                       goto fail;
 
                /*
                 * Now populate the array of argument strings.
@@ -149,6 +148,8 @@ dtrace_psinfo_t *dtrace_psinfo_alloc(struct task_struct *task)
                }
 
                psinfo->envp = vmalloc((envc + 1) * sizeof(char *));
+               if (psinfo->envp == NULL)
+                       goto fail;
 
                /*
                 * Now populate the array of environment variable strings.
@@ -161,6 +162,19 @@ dtrace_psinfo_t *dtrace_psinfo_alloc(struct task_struct *task)
        }
 
        return psinfo;
+
+fail:
+       pr_warning("%s: cannot allocate DTrace psinfo structure\n", __func__);
+       if (psinfo) {
+               if (psinfo->argv == NULL)
+                       vfree(psinfo->argv);
+               if (psinfo->envp == NULL)
+                       vfree(psinfo->envp);
+
+               kfree(psinfo);
+       }
+
+       return NULL;
 }
 
 static DEFINE_SPINLOCK(psinfo_lock);
@@ -554,14 +568,21 @@ void dtrace_disable(void)
 }
 EXPORT_SYMBOL(dtrace_disable);
 
-void dtrace_invop_add(uint8_t (*func)(struct pt_regs *))
+int dtrace_invop_add(uint8_t (*func)(struct pt_regs *))
 {
        dtrace_invop_hdlr_t     *hdlr;
 
        hdlr = kmalloc(sizeof(dtrace_invop_hdlr_t), GFP_KERNEL);
+       if (hdlr == NULL) {
+               pr_warn("Failed to add invop handler: out of memory\n");
+               return -ENOMEM;
+       }
+
        hdlr->dtih_func = func;
        hdlr->dtih_next = dtrace_invop_hdlrs;
        dtrace_invop_hdlrs = hdlr;
+
+       return 0;
 }
 EXPORT_SYMBOL(dtrace_invop_add);
 
@@ -571,7 +592,7 @@ void dtrace_invop_remove(uint8_t (*func)(struct pt_regs *))
 
        for (;;) {
                if (hdlr == NULL)
-                       pr_err("attempt to remove non-existant invop handler");
+                       return;
 
                if (hdlr->dtih_func == func)
                        break;