Patch "farsync: fix off-by-one bug in fst_add_one" has been added to the 4.4-stable tree
Subsystems (3)
This is a note to let you know that I've just added the patch titled
farsync: fix off-by-one bug in fst_add_one
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
farsync-fix-off-by-one-bug-in-fst_add_one.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.
Quoted 1 line
From foo@baz Sat Apr 16 10:02:53 PDT 2016
From: Arnd Bergmann <[email protected]>
Date: Mon, 14 Mar 2016 15:18:35 +0100
Subject: farsync: fix off-by-one bug in fst_add_one
From: Arnd Bergmann <[email protected]>
[ Upstream commit e725a66c0202b5f36c2f9d59d26a65c53bbf21f7 ]
gcc-6 finds an out of bounds access in the fst_add_one function when calculating the end of the mmio area:
drivers/net/wan/farsync.c: In function 'fst_add_one':drivers/net/wan/farsync.c:418:53: error: index 2 denotes an offset greater than size of 'u8[2][8192] {aka unsigned char[2][8192]}' [-Werror=array-bounds]
#define BUF_OFFSET(X) (BFM_BASE + offsetof(struct buf_window, X))
^
include/linux/compiler-gcc.h:158:21: note: in definition of macro '__compiler_offsetof'
__builtin_offsetof(a, b)
^
drivers/net/wan/farsync.c:418:37: note: in expansion of macro 'offsetof'
#define BUF_OFFSET(X) (BFM_BASE + offsetof(struct buf_window, X))
^~~~~~~~drivers/net/wan/farsync.c:2519:36: note: in expansion of macro 'BUF_OFFSET'
+ BUF_OFFSET ( txBuffer[i][NUM_TX_BUFFER][0]); ^~~~~~~~~~
The warning is correct, but not critical because this appears to be a write-only variable that is set by each WAN driver but never accessed afterwards.
I'm taking the minimal fix here, using the correct pointer by pointing 'mem_end' to the last byte inside of the register area as all other WAN drivers do, rather than the first byte outside of it. An alternative would be to just remove the mem_end member entirely.
--- drivers/net/wan/farsync.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/net/wan/farsync.c +1 -1
@@ -2516,7 +2516,7 @@ fst_add_one(struct pci_dev *pdev, const dev->mem_start = card->phys_mem +BUF_OFFSET ( txBuffer[i][0 ][0 ]); dev->mem_end = card->phys_mem - +BUF_OFFSET ( txBuffer[i][NUM_TX_BUFFER ][0 ]); + +BUF_OFFSET ( txBuffer[i][NUM_TX_BUFFER -1 ][LEN_RX_BUFFER -1 ]); dev->base_addr = card->pci_conf; dev->irq = card->irq;
Patches currently in stable-queue which might be from [email protected] are
queue-4.4/farsync-fix-off-by-one-bug-in-fst_add_one.patch queue-4.4/ath9k-fix-buffer-overrun-for-ar9287.patch queue-4.4/hwmon-max1111-return-enodev-from-max1111_read_channel-if-not-instantiated.patch queue-4.4/mlx4-add-missing-braces-in-verify_qp_parameters.patch