pstore/ram: Fix bounds checks for mem_size, record_size, console_size and ftrace_size

The bounds check in ramoops_init_prz was incorrect and ramoops_init_przs
had no check. Additionally, ramoops_init_przs allows record_size to be 0,
but ramoops_pstore_write_buf would always crash in this case.

Signed-off-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>

diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index 8741cea6253c61d86c1f6400e98d3cb3f82f901c..dba70e53b72c427bcbee855203698f43955410cb 100644 (file)
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -189,7 +189,7 @@ static int notrace ramoops_pstore_write_buf(enum pstore_type_id type,
                                            struct pstore_info *psi)
 {
        struct ramoops_context *cxt = psi->data;
-       struct persistent_ram_zone *prz = cxt->przs[cxt->dump_write_cnt];
+       struct persistent_ram_zone *prz;
        size_t hlen;
 
        if (type == PSTORE_TYPE_CONSOLE) {
@@ -226,6 +226,11 @@ static int notrace ramoops_pstore_write_buf(enum pstore_type_id type,
        if (part != 1)
                return -ENOSPC;
 
+       if (!cxt->przs)
+               return -ENOSPC;
+
+       prz = cxt->przs[cxt->dump_write_cnt];
+
        hlen = ramoops_write_kmsg_hdr(prz);
        if (size + hlen > prz->buffer_size)
                size = prz->buffer_size - hlen;
@@ -297,6 +302,11 @@ static int __devinit ramoops_init_przs(struct device *dev,
        if (!cxt->record_size)
                return 0;
 
+       if (*paddr + dump_mem_sz - cxt->phys_addr > cxt->size) {
+               dev_err(dev, "no room for dumps\n");
+               return -ENOMEM;
+       }
+
        cxt->max_dump_cnt = dump_mem_sz / cxt->record_size;
        if (!cxt->max_dump_cnt)
                return -ENOMEM;
@@ -335,8 +345,12 @@ static int __devinit ramoops_init_prz(struct device *dev,
        if (!sz)
                return 0;
 
-       if (*paddr + sz > *paddr + cxt->size)
+       if (*paddr + sz - cxt->phys_addr > cxt->size) {
+               dev_err(dev, "no room for mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
+                       sz, (unsigned long long)*paddr,
+                       cxt->size, (unsigned long long)cxt->phys_addr);
                return -ENOMEM;
+       }
 
        *prz = persistent_ram_new(*paddr, sz, sig, cxt->ecc_size);
        if (IS_ERR(*prz)) {