diff options
| author | Guenter Roeck <linux@roeck-us.net> | 2022-05-31 15:29:51 -0700 |
|---|---|---|
| committer | akpm <akpm@linux-foundation.org> | 2022-06-16 19:58:20 -0700 |
| commit | 0cc011c576aaa4de505046f7a6c90933d7c749a9 (patch) | |
| tree | 8ca5e4ecd17087ab745b2e65cef0973ad749c351 | |
| parent | 53fd5ffbb5197b8cc2d73d2bbc0f688afd45736c (diff) | |
lib/list_debug.c: Detect uninitialized lists
In some circumstances, attempts are made to add entries to or to remove
entries from an uninitialized list. A prime example is
amdgpu_bo_vm_destroy(): It is indirectly called from
ttm_bo_init_reserved() if that function fails, and tries to remove an
entry from a list. However, that list is only initialized in
amdgpu_bo_create_vm() after the call to ttm_bo_init_reserved() returned
success. This results in crashes such as
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
CPU: 1 PID: 1479 Comm: chrome Not tainted 5.10.110-15768-g29a72e65dae5
Hardware name: Google Grunt/Grunt, BIOS Google_Grunt.11031.149.0 07/15/2020
RIP: 0010:__list_del_entry_valid+0x26/0x7d
...
Call Trace:
amdgpu_bo_vm_destroy+0x48/0x8b
ttm_bo_init_reserved+0x1d7/0x1e0
amdgpu_bo_create+0x212/0x476
? amdgpu_bo_user_destroy+0x23/0x23
? kmem_cache_alloc+0x60/0x271
amdgpu_bo_create_vm+0x40/0x7d
amdgpu_vm_pt_create+0xe8/0x24b
...
Check if the list's prev and next pointers are NULL to catch such problems.
Link: https://lkml.kernel.org/r/20220531222951.92073-1-linux@roeck-us.net
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | lib/list_debug.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/lib/list_debug.c b/lib/list_debug.c index 9daa3fb9d1cd..d98d43f80958 100644 --- a/lib/list_debug.c +++ b/lib/list_debug.c @@ -20,7 +20,11 @@ bool __list_add_valid(struct list_head *new, struct list_head *prev, struct list_head *next) { - if (CHECK_DATA_CORRUPTION(next->prev != prev, + if (CHECK_DATA_CORRUPTION(prev == NULL, + "list_add corruption. prev is NULL.\n") || + CHECK_DATA_CORRUPTION(next == NULL, + "list_add corruption. next is NULL.\n") || + CHECK_DATA_CORRUPTION(next->prev != prev, "list_add corruption. next->prev should be prev (%px), but was %px. (next=%px).\n", prev, next->prev, next) || CHECK_DATA_CORRUPTION(prev->next != next, @@ -42,7 +46,11 @@ bool __list_del_entry_valid(struct list_head *entry) prev = entry->prev; next = entry->next; - if (CHECK_DATA_CORRUPTION(next == LIST_POISON1, + if (CHECK_DATA_CORRUPTION(next == NULL, + "list_del corruption, %px->next is NULL\n", entry) || + CHECK_DATA_CORRUPTION(prev == NULL, + "list_del corruption, %px->prev is NULL\n", entry) || + CHECK_DATA_CORRUPTION(next == LIST_POISON1, "list_del corruption, %px->next is LIST_POISON1 (%px)\n", entry, LIST_POISON1) || CHECK_DATA_CORRUPTION(prev == LIST_POISON2, |