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authorJann Horn <jannh@google.com>2019-05-04 15:56:08 +0200
committerOded Gabbay <oded.gabbay@gmail.com>2019-05-24 22:46:15 +0300
commit8438846cce61e284a22316c13aa4b63772963070 (patch)
tree48086674deda57429a2e19443a6964463f2f3db2 /drivers/misc
parent2add64ebaea25dfada27b3332b1c982f9fc5ae64 (diff)
habanalabs: fix debugfs code
This fixes multiple things in the habanalabs debugfs code, in particular: - mmu_write() was unnecessarily verbose, copying around between multiple buffers - mmu_write() could write a user-specified, unbounded amount of userspace memory into a kernel buffer (out-of-bounds write) - multiple debugfs read handlers ignored the user-supplied count, potentially corrupting out-of-bounds userspace data - hl_device_read() was unnecessarily verbose - hl_device_write() could read uninitialized stack memory - multiple debugfs read handlers copied terminating null characters to userspace Signed-off-by: Jann Horn <jannh@google.com> Reviewed-by: Oded Gabbay <oded.gabbay@gmail.com> Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com> Cc: stable@vger.kernel.org
Diffstat (limited to 'drivers/misc')
-rw-r--r--drivers/misc/habanalabs/debugfs.c60
1 files changed, 18 insertions, 42 deletions
diff --git a/drivers/misc/habanalabs/debugfs.c b/drivers/misc/habanalabs/debugfs.c
index a4447699ff4e..0ce5621c1324 100644
--- a/drivers/misc/habanalabs/debugfs.c
+++ b/drivers/misc/habanalabs/debugfs.c
@@ -459,41 +459,31 @@ static ssize_t mmu_write(struct file *file, const char __user *buf,
struct hl_debugfs_entry *entry = s->private;
struct hl_dbg_device_entry *dev_entry = entry->dev_entry;
struct hl_device *hdev = dev_entry->hdev;
- char kbuf[MMU_KBUF_SIZE], asid_kbuf[MMU_ASID_BUF_SIZE],
- addr_kbuf[MMU_ADDR_BUF_SIZE];
+ char kbuf[MMU_KBUF_SIZE];
char *c;
ssize_t rc;
if (!hdev->mmu_enable)
return count;
- memset(kbuf, 0, sizeof(kbuf));
- memset(asid_kbuf, 0, sizeof(asid_kbuf));
- memset(addr_kbuf, 0, sizeof(addr_kbuf));
-
+ if (count > sizeof(kbuf) - 1)
+ goto err;
if (copy_from_user(kbuf, buf, count))
goto err;
-
- kbuf[MMU_KBUF_SIZE - 1] = 0;
+ kbuf[count] = 0;
c = strchr(kbuf, ' ');
if (!c)
goto err;
+ *c = '\0';
- memcpy(asid_kbuf, kbuf, c - kbuf);
-
- rc = kstrtouint(asid_kbuf, 10, &dev_entry->mmu_asid);
+ rc = kstrtouint(kbuf, 10, &dev_entry->mmu_asid);
if (rc)
goto err;
- c = strstr(kbuf, " 0x");
- if (!c)
+ if (strncmp(c+1, "0x", 2))
goto err;
-
- c += 3;
- memcpy(addr_kbuf, c, (kbuf + count) - c);
-
- rc = kstrtoull(addr_kbuf, 16, &dev_entry->mmu_addr);
+ rc = kstrtoull(c+3, 16, &dev_entry->mmu_addr);
if (rc)
goto err;
@@ -600,10 +590,8 @@ static ssize_t hl_data_read32(struct file *f, char __user *buf,
}
sprintf(tmp_buf, "0x%08x\n", val);
- rc = simple_read_from_buffer(buf, strlen(tmp_buf) + 1, ppos, tmp_buf,
- strlen(tmp_buf) + 1);
-
- return rc;
+ return simple_read_from_buffer(buf, count, ppos, tmp_buf,
+ strlen(tmp_buf));
}
static ssize_t hl_data_write32(struct file *f, const char __user *buf,
@@ -645,7 +633,6 @@ static ssize_t hl_get_power_state(struct file *f, char __user *buf,
struct hl_dbg_device_entry *entry = file_inode(f)->i_private;
struct hl_device *hdev = entry->hdev;
char tmp_buf[200];
- ssize_t rc;
int i;
if (*ppos)
@@ -660,10 +647,8 @@ static ssize_t hl_get_power_state(struct file *f, char __user *buf,
sprintf(tmp_buf,
"current power state: %d\n1 - D0\n2 - D3hot\n3 - Unknown\n", i);
- rc = simple_read_from_buffer(buf, strlen(tmp_buf) + 1, ppos, tmp_buf,
- strlen(tmp_buf) + 1);
-
- return rc;
+ return simple_read_from_buffer(buf, count, ppos, tmp_buf,
+ strlen(tmp_buf));
}
static ssize_t hl_set_power_state(struct file *f, const char __user *buf,
@@ -716,8 +701,8 @@ static ssize_t hl_i2c_data_read(struct file *f, char __user *buf,
}
sprintf(tmp_buf, "0x%02x\n", val);
- rc = simple_read_from_buffer(buf, strlen(tmp_buf) + 1, ppos, tmp_buf,
- strlen(tmp_buf) + 1);
+ rc = simple_read_from_buffer(buf, count, ppos, tmp_buf,
+ strlen(tmp_buf));
return rc;
}
@@ -806,18 +791,9 @@ static ssize_t hl_led2_write(struct file *f, const char __user *buf,
static ssize_t hl_device_read(struct file *f, char __user *buf,
size_t count, loff_t *ppos)
{
- char tmp_buf[200];
- ssize_t rc;
-
- if (*ppos)
- return 0;
-
- sprintf(tmp_buf,
- "Valid values: disable, enable, suspend, resume, cpu_timeout\n");
- rc = simple_read_from_buffer(buf, strlen(tmp_buf) + 1, ppos, tmp_buf,
- strlen(tmp_buf) + 1);
-
- return rc;
+ static const char *help =
+ "Valid values: disable, enable, suspend, resume, cpu_timeout\n";
+ return simple_read_from_buffer(buf, count, ppos, help, strlen(help));
}
static ssize_t hl_device_write(struct file *f, const char __user *buf,
@@ -825,7 +801,7 @@ static ssize_t hl_device_write(struct file *f, const char __user *buf,
{
struct hl_dbg_device_entry *entry = file_inode(f)->i_private;
struct hl_device *hdev = entry->hdev;
- char data[30];
+ char data[30] = {0};
/* don't allow partial writes */
if (*ppos != 0)