Erick Archer says:
====================
mana: Add flex array to struct mana_cfg_rx_steer_req_v2 (part)
The "struct mana_cfg_rx_steer_req_v2" uses a dynamically sized set of
trailing elements. Specifically, it uses a "mana_handle_t" array. So,
use the preferred way in the kernel declaring a flexible array [1].
At the same time, prepare for the coming implementation by GCC and Clang
of the __counted_by attribute. Flexible array members annotated with
__counted_by can have their accesses bounds-checked at run-time via
CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for
strcpy/memcpy-family functions).
Also, avoid the open-coded arithmetic in the memory allocator functions
[2] using the "struct_size" macro.
Moreover, use the "offsetof" helper to get the indirect table offset
instead of the "sizeof" operator and avoid the open-coded arithmetic in
pointers using the new flex member. This new structure member also allow
us to remove the "req_indir_tab" variable since it is no longer needed.
Now, it is also possible to use the "flex_array_size" helper to compute
the size of these trailing elements in the "memcpy" function.
Specifically, the first commit adds the flex member and the patches 2 and
3 refactor the consumers of the "struct mana_cfg_rx_steer_req_v2".
This code was detected with the help of Coccinelle, and audited and
modified manually. The Coccinelle script used to detect this code pattern
is the following:
virtual report
@rule1@
type t1;
type t2;
identifier i0;
identifier i1;
identifier i2;
identifier ALLOC =~ "kmalloc|kzalloc|kmalloc_node|kzalloc_node|vmalloc|vzalloc|kvmalloc|kvzalloc";
position p1;
@@
i0 = sizeof(t1) + sizeof(t2) * i1;
...
i2 = ALLOC@p1(..., i0, ...);
@script:python depends on report@
p1 << rule1.p1;
@@
msg = "WARNING: verify allocation on line %s" % (p1[0].line)
coccilib.report.print_report(p1[0],msg)
Link: https://www.kernel.org/doc/html/next/process/deprecated.html#zero-length-and-one-element-arrays [1]
Link: https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [2]
v1: https://lore.kernel.org/linux-hardening/AS8PR02MB7237974EF1B9BAFA618166C38B382@AS8PR02MB7237.eurprd02.prod.outlook.com/
v2: https://lore.kernel.org/linux-hardening/AS8PR02MB723729C5A63F24C312FC9CD18B3F2@AS8PR02MB7237.eurprd02.prod.outlook.com/
====================
Link: https://lore.kernel.org/r/AS8PR02MB72374BD1B23728F2E3C3B1A18B022@AS8PR02MB7237.eurprd02.prod.outlook.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
0e36c21d76