kernel/linux.git/drivers/mailbox/mailbox-test.c, branch v6.12.91

mailbox: mailbox-test: make data_ready a per-instance variable

2026-05-23T11:04:52+00:00

[ Upstream commit 6e937f4e769e60947909e3525965f0137b9039e8 ] While not the default case, multiple tests can be run simultaneously. Then, data_ready being a global variable will be overwritten and the per-instance lock will not help. Turn the global variable into a per-instance one to avoid this problem. Fixes: e339c80af95e ("mailbox: mailbox-test: don't rely on rx_buffer content to signal data ready") Signed-off-by: Wolfram Sang Signed-off-by: Jassi Brar Signed-off-by: Sasha Levin

mailbox: mailbox-test: initialize struct earlier

2026-05-23T11:04:52+00:00

[ Upstream commit bbcf9af68bfedb3d9cc3c7eae62f5c844d8b78b9 ] The waitqueue must be initialized before the debugfs files are created because from that time, requests from userspace can already be made. Similarily, drvdata and spinlock needs to be initialized before we request the channel, otherwise dangling irqs might run into problems like a NULL pointer exception. Fixes: 8ea4484d0c2b ("mailbox: Add generic mechanism for testing Mailbox Controllers") Signed-off-by: Wolfram Sang Signed-off-by: Jassi Brar Signed-off-by: Sasha Levin

mailbox: mailbox-test: don't free the reused channel

2026-05-23T11:04:51+00:00

[ Upstream commit 88ebadbf0deefdaccdab868b44ff70a0a257f473 ] The RX channel can be aliased to the TX channel if it has a different MMIO. This special case needs to be handled when freeing the channels otherwise a double-free occurs. Fixes: 8ea4484d0c2b ("mailbox: Add generic mechanism for testing Mailbox Controllers") Signed-off-by: Wolfram Sang Signed-off-by: Jassi Brar Signed-off-by: Sasha Levin

mailbox: mailbox-test: free channels on probe error

2026-05-23T11:04:51+00:00

[ Upstream commit c02053a9055d5fdfd32432287cca8958db1d5bc5 ] On probe error, free the previously obtained channels. This not only prevents a leak, but also UAF scenarios because the client structure will be removed nonetheless because it was allocated with devm. Link: https://sashiko.dev/#/patchset/20260327151217.5327-2-wsa%2Brenesas%40sang-engineering.com Fixes: 8ea4484d0c2b ("mailbox: Add generic mechanism for testing Mailbox Controllers") Signed-off-by: Wolfram Sang Signed-off-by: Jassi Brar Signed-off-by: Sasha Levin

mailbox: mailbox-test: Fix debugfs_create_dir error checking

2025-12-06T21:24:56+00:00

[ Upstream commit 3acf1028f5003731977f750a7070f3321a9cb740 ] The debugfs_create_dir() function returns ERR_PTR() on error, not NULL. The current null-check fails to catch errors. Use IS_ERR() to correctly check for errors. Fixes: 8ea4484d0c2b ("mailbox: Add generic mechanism for testing Mailbox Controllers") Signed-off-by: Haotian Zhang Signed-off-by: Jassi Brar Signed-off-by: Sasha Levin

mailbox: mailbox-test: Convert to platform remove callback returning void

2024-01-14T05:08:51+00:00

The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is ignored (apart from emitting a warning) and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new(), which already returns void. Eventually after all drivers are converted, .remove_new() will be renamed to .remove(). Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Signed-off-by: Uwe Kleine-König Signed-off-by: Jassi Brar

mailbox: mailbox-test: Fix an error check in mbox_test_probe()

2023-09-05T15:10:42+00:00

mbox_test_request_channel() function returns NULL or error value embedded in the pointer (PTR_ERR). Evaluate the return value using IS_ERR_OR_NULL. Signed-off-by: Minjie Du Signed-off-by: Jassi Brar

mailbox: mailbox-test: Use devm_platform_get_and_ioremap_resource()

2023-09-05T15:10:42+00:00

Convert platform_get_resource(), devm_ioremap_resource() to a single call to devm_platform_get_and_ioremap_resource(), as this is exactly what this function does. Signed-off-by: Yangtao Li Signed-off-by: Jassi Brar

mailbox: mailbox-test: fix a locking issue in mbox_test_message_write()

2023-05-31T18:26:44+00:00

There was a bug where this code forgot to unlock the tdev->mutex if the kzalloc() failed. Fix this issue, by moving the allocation outside the lock. Fixes: 2d1e952a2b8e ("mailbox: mailbox-test: Fix potential double-free in mbox_test_message_write()") Signed-off-by: Dan Carpenter Reviewed-by: Lee Jones Signed-off-by: Jassi Brar

mailbox: mailbox-test: Fix potential double-free in mbox_test_message_write()

2023-05-04T05:53:31+00:00

If a user can make copy_from_user() fail, there is a potential for UAF/DF due to a lack of locking around the allocation, use and freeing of the data buffers. This issue is not theoretical. I managed to author a POC for it: BUG: KASAN: double-free in kfree+0x5c/0xac Free of addr ffff29280be5de00 by task poc/356 CPU: 1 PID: 356 Comm: poc Not tainted 6.1.0-00001-g961aa6552c04-dirty #20 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace.part.0+0xe0/0xf0 show_stack+0x18/0x40 dump_stack_lvl+0x64/0x80 print_report+0x188/0x48c kasan_report_invalid_free+0xa0/0xc0 ____kasan_slab_free+0x174/0x1b0 __kasan_slab_free+0x18/0x24 __kmem_cache_free+0x130/0x2e0 kfree+0x5c/0xac mbox_test_message_write+0x208/0x29c full_proxy_write+0x90/0xf0 vfs_write+0x154/0x440 ksys_write+0xcc/0x180 __arm64_sys_write+0x44/0x60 invoke_syscall+0x60/0x190 el0_svc_common.constprop.0+0x7c/0x160 do_el0_svc+0x40/0xf0 el0_svc+0x2c/0x6c el0t_64_sync_handler+0xf4/0x120 el0t_64_sync+0x18c/0x190 Allocated by task 356: kasan_save_stack+0x3c/0x70 kasan_set_track+0x2c/0x40 kasan_save_alloc_info+0x24/0x34 __kasan_kmalloc+0xb8/0xc0 kmalloc_trace+0x58/0x70 mbox_test_message_write+0x6c/0x29c full_proxy_write+0x90/0xf0 vfs_write+0x154/0x440 ksys_write+0xcc/0x180 __arm64_sys_write+0x44/0x60 invoke_syscall+0x60/0x190 el0_svc_common.constprop.0+0x7c/0x160 do_el0_svc+0x40/0xf0 el0_svc+0x2c/0x6c el0t_64_sync_handler+0xf4/0x120 el0t_64_sync+0x18c/0x190 Freed by task 357: kasan_save_stack+0x3c/0x70 kasan_set_track+0x2c/0x40 kasan_save_free_info+0x38/0x5c ____kasan_slab_free+0x13c/0x1b0 __kasan_slab_free+0x18/0x24 __kmem_cache_free+0x130/0x2e0 kfree+0x5c/0xac mbox_test_message_write+0x208/0x29c full_proxy_write+0x90/0xf0 vfs_write+0x154/0x440 ksys_write+0xcc/0x180 __arm64_sys_write+0x44/0x60 invoke_syscall+0x60/0x190 el0_svc_common.constprop.0+0x7c/0x160 do_el0_svc+0x40/0xf0 el0_svc+0x2c/0x6c el0t_64_sync_handler+0xf4/0x120 el0t_64_sync+0x18c/0x190 Signed-off-by: Lee Jones Signed-off-by: Jassi Brar