[PATCH 05/14] nubus: Validate slot resource IDs

Finn Thain
2017-11-11T06:16:05Z

While we are here, include the slot number in the related error messages.

Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
---
drivers/nubus/nubus.c | 25 +++++++++++++++++++------
1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/drivers/nubus/nubus.c b/drivers/nubus/nubus.c
index 5607e58d5ca2..5799ff343d84 100644
--- a/drivers/nubus/nubus.c
+++ b/drivers/nubus/nubus.c
@@ -615,7 +615,7 @@ static int __init nubus_get_board_resource(struct nubus_board *board, int slot,
nbtdata[0], nbtdata[1], nbtdata[2], nbtdata[3]);
if (nbtdata[0] != 1 || nbtdata[1] != 0 ||
nbtdata[2] != 0 || nbtdata[3] != 0)
- pr_err("this sResource is not a board resource!\n");
+ pr_err("Slot %X: sResource is not a board resource!\n", slot);
break;
}
case NUBUS_RESID_NAME:
@@ -670,6 +670,7 @@ static struct nubus_board * __init nubus_add_board(int slot, int bytelanes)
unsigned long dpat;
struct nubus_dir dir;
struct nubus_dirent ent;
+ int prev_resid = -1;

/* Move to the start of the format block */
rp = nubus_rom_addr(slot);
@@ -709,10 +710,10 @@ static struct nubus_board * __init nubus_add_board(int slot, int bytelanes)

/* Directory offset should be small and negative... */
if (!(board->doffset & 0x00FF0000))
- pr_warn("Dodgy doffset!\n");
+ pr_warn("Slot %X: Dodgy doffset!\n", slot);
dpat = nubus_get_rom(&rp, 4, bytelanes);
if (dpat != NUBUS_TEST_PATTERN)
- pr_warn("Wrong test pattern %08lx!\n", dpat);
+ pr_warn("Slot %X: Wrong test pattern %08lx!\n", slot, dpat);

/*
* I wonder how the CRC is meant to work -
@@ -738,12 +739,15 @@ static struct nubus_board * __init nubus_add_board(int slot, int bytelanes)
for each of them. */
if (nubus_readdir(&dir, &ent) == -1) {
/* We can't have this! */
- pr_err("Board resource not found!\n");
+ pr_err("Slot %X: Board resource not found!\n", slot);
return NULL;
- } else {
- nubus_get_board_resource(board, slot, &ent);
}

+ if (ent.type < 1 || ent.type > 127)
+ pr_warn("Slot %X: Board resource ID is invalid!\n", slot);
+
+ nubus_get_board_resource(board, slot, &ent);
+
while (nubus_readdir(&dir, &ent) != -1) {
struct nubus_dev *dev;
struct nubus_dev **devp;
@@ -752,6 +756,15 @@ static struct nubus_board * __init nubus_add_board(int slot, int bytelanes)
if (dev == NULL)
continue;

+ /* Resources should appear in ascending ID order. This sanity
+ * check prevents duplicate resource IDs.
+ */
+ if (dev->resid <= prev_resid) {
+ kfree(dev);
+ continue;
+ }
+ prev_resid = dev->resid;
+
/* We zeroed this out above */
if (board->first_dev == NULL)
board->first_dev = dev;
--
2.13.6