On Wed, 12 Jul 2023 at 01:01, Isaac J. Manjarres
<isaacmanjarres@xxxxxxxxxx> wrote:
>
> When allocating the 2D array for handling IRQ type registers in
> regmap_add_irq_chip_fwnode(), the intent is to allocate a matrix
> with num_config_bases rows and num_config_regs columns.
>
> This is currently handled by allocating a buffer to hold a pointer for
> each row (i.e. num_config_bases). After that, the logic attempts to
> allocate the memory required to hold the register configuration for
> each row. However, instead of doing this allocation for each row
> (i.e. num_config_bases allocations), the logic erroneously does this
> allocation num_config_regs number of times.
>
> This scenario can lead to out-of-bounds accesses when num_config_regs
> is greater than num_config_bases. Fix this by updating the terminating
> condition of the loop that allocates the memory for holding the register
> configuration to allocate memory only for each row in the matrix.
>
> Amit Pundir reported a crash that was occurring on his db845c device
> due to memory corruption (see "Closes" tag for Amit's report). The KASAN
> report below helped narrow it down to this issue:
Tested-by: Amit Pundir <amit.pundir@xxxxxxxxxx> # tested on Dragonboard 845c
>
> [ 14.033877][ T1] ==================================================================
> [ 14.042507][ T1] BUG: KASAN: invalid-access in regmap_add_irq_chip_fwnode+0x594/0x1364
> [ 14.050796][ T1] Write of size 8 at addr 06ffff8081021850 by task init/1
> [ 14.057841][ T1] Pointer tag: [06], memory tag: [fe]
> [ 14.063124][ T1]
> [ 14.065349][ T1] CPU: 2 PID: 1 Comm: init Tainted: G W E 6.4.0-mainline-g6a4b67fef3e2 #1
> [ 14.075014][ T1] Hardware name: Thundercomm Dragonboard 845c (DT)
> [ 14.081432][ T1] Call trace:
> [ 14.084618][ T1] dump_backtrace+0xe8/0x108
> [ 14.089144][ T1] show_stack+0x18/0x30
> [ 14.093215][ T1] dump_stack_lvl+0x50/0x6c
> [ 14.097642][ T1] print_report+0x178/0x4c0
> [ 14.102070][ T1] kasan_report+0xd4/0x12c
> [ 14.106407][ T1] kasan_tag_mismatch+0x28/0x40
> [ 14.111178][ T1] __hwasan_tag_mismatch+0x2c/0x5c
> [ 14.116222][ T1] regmap_add_irq_chip_fwnode+0x594/0x1364
> [ 14.121961][ T1] devm_regmap_add_irq_chip+0xb8/0x144
> [ 14.127346][ T1] wcd934x_slim_status+0x210/0x28c [wcd934x]
> [ 14.133307][ T1] slim_device_alloc_laddr+0x1ac/0x1ec [slimbus]
> [ 14.139669][ T1] slim_device_probe+0x80/0x124 [slimbus]
> [ 14.145394][ T1] really_probe+0x250/0x4d8
> [ 14.149826][ T1] __driver_probe_device+0x104/0x1ac
> [ 14.155041][ T1] driver_probe_device+0x80/0x218
> [ 14.159990][ T1] __driver_attach+0x19c/0x2e4
> [ 14.164678][ T1] bus_for_each_dev+0x158/0x1b4
> [ 14.169454][ T1] driver_attach+0x34/0x44
> [ 14.173790][ T1] bus_add_driver+0x1fc/0x328
> [ 14.178390][ T1] driver_register+0xdc/0x1b4
> [ 14.182995][ T1] __slim_driver_register+0x6c/0x84 [slimbus]
> [ 14.189068][ T1] init_module+0x20/0xfe4 [wcd934x]
> [ 14.194219][ T1] do_one_initcall+0x110/0x418
> [ 14.198916][ T1] do_init_module+0x124/0x30c
> [ 14.203521][ T1] load_module+0x1938/0x1ab0
> [ 14.208034][ T1] __arm64_sys_finit_module+0x110/0x138
> [ 14.213509][ T1] invoke_syscall+0x70/0x170
> [ 14.218015][ T1] el0_svc_common+0xf0/0x138
> [ 14.222523][ T1] do_el0_svc+0x40/0xb8
> [ 14.226596][ T1] el0_svc+0x2c/0x78
> [ 14.230405][ T1] el0t_64_sync_handler+0x68/0xb4
> [ 14.235354][ T1] el0t_64_sync+0x19c/0x1a0
> [ 14.239778][ T1]
> [ 14.242004][ T1] The buggy address belongs to the object at ffffff8081021850
> [ 14.242004][ T1] which belongs to the cache kmalloc-8 of size 8
> [ 14.255669][ T1] The buggy address is located 0 bytes inside of
> [ 14.255669][ T1] 8-byte region [ffffff8081021850, ffffff8081021858)
> [ 14.255685][ T1]
> [ 14.255689][ T1] The buggy address belongs to the physical page:
> [ 14.255699][ T1] page:0000000080887a30 refcount:1 mapcount:0 mapping:0000000000000000 index:0x85ffff8081021ee0 pfn:0x101021
> [ 14.275062][ T1] flags: 0x4000000000000200(slab|zone=1|kasantag=0x0)
> [ 14.275078][ T1] page_type: 0xffffffff()
> [ 14.275091][ T1] raw: 4000000000000200 49ffff8080002200 dead000000000122 0000000000000000
> [ 14.275103][ T1] raw: 85ffff8081021ee0 00000000810000ea 00000001ffffffff 0000000000000000
> [ 14.275110][ T1] page dumped because: kasan: bad access detected
> [ 14.275116][ T1]
> [ 14.275119][ T1] Memory state around the buggy address:
> [ 14.275125][ T1] ffffff8081021600: fe fe fe 9a fe fe 5b 3c fe fe c9 fe b4 3f fe 54
> [ 14.275133][ T1] ffffff8081021700: fe fe ad 6b fe fe fe 87 fe fe 39 c9 fe 03 fe ea
> [ 14.275143][ T1] >ffffff8081021800: fe fe e1 fe 06 fe fe 21 fe fe e7 fe de fe fe 70
> [ 14.275149][ T1] ^
> [ 14.371674][ T1] ffffff8081021900: d7 fe fe 87 fe a0 fe fe fe 80 e0 f0 05 fe fe fe
> [ 14.379667][ T1] ffffff8081021a00: 94 fe 31 fe fe e5 c8 00 d0 fe a1 fe fe e2 e5 fe
> [ 14.387664][ T1] ==================================================================
>
> Fixes: faa87ce9196d ("regmap-irq: Introduce config registers for irq types")
> Reported-by: Amit Pundir <amit.pundir@xxxxxxxxxx>
> Closes: https://lore.kernel.org/all/CAMi1Hd04mu6JojT3y6wyN2YeVkPR5R3qnkKJ8iR8if_YByCn4w@xxxxxxxxxxxxxx/
> Tested-by: John Stultz <jstultz@xxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx # v6.0+
> Cc: Aidan MacDonald <aidanmacdonald.0x0@xxxxxxxxx>
> Cc: Saravana Kannan <saravanak@xxxxxxxxxx>
> Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
> Signed-off-by: Isaac J. Manjarres <isaacmanjarres@xxxxxxxxxx>
> ---
> drivers/base/regmap/regmap-irq.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/base/regmap/regmap-irq.c b/drivers/base/regmap/regmap-irq.c
> index ced0dcf86e0b..45fd13ef13fc 100644
> --- a/drivers/base/regmap/regmap-irq.c
> +++ b/drivers/base/regmap/regmap-irq.c
> @@ -717,7 +717,7 @@ int regmap_add_irq_chip_fwnode(struct fwnode_handle *fwnode,
> if (!d->config_buf)
> goto err_alloc;
>
> - for (i = 0; i < chip->num_config_regs; i++) {
> + for (i = 0; i < chip->num_config_bases; i++) {
> d->config_buf[i] = kcalloc(chip->num_config_regs,
> sizeof(**d->config_buf),
> GFP_KERNEL);
> --
> 2.41.0.255.g8b1d071c50-goog
>
