From: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com> mainline inclusion from mainline-v7.0-rc1 commit 5a19302cab5cec7ae7f1a60c619951e6c17d8742 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/15122 CVE: CVE-2026-45878 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- The address watch clear code receives watch_id as an unsigned value (u32), but some helper functions were using a signed int and checked bits by shifting with watch_id. If a very large watch_id is passed from userspace, it can be converted to a negative value. This can cause invalid shifts and may access memory outside the watch_points array. drm/amdkfd: Fix watch_id bounds checking in debug address watch v2 Fix this by checking that watch_id is within MAX_WATCH_ADDRESSES before using it. Also use BIT(watch_id) to test and clear bits safely. This keeps the behavior unchanged for valid watch IDs and avoids undefined behavior for invalid ones. Fixes the below: drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_debug.c:448 kfd_dbg_trap_clear_dev_address_watch() error: buffer overflow 'pdd->watch_points' 4 <= u32max user_rl='0-3,2147483648-u32max' uncapped drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_debug.c 433 int kfd_dbg_trap_clear_dev_address_watch(struct kfd_process_device *pdd, 434 uint32_t watch_id) 435 { 436 int r; 437 438 if (!kfd_dbg_owns_dev_watch_id(pdd, watch_id)) kfd_dbg_owns_dev_watch_id() doesn't check for negative values so if watch_id is larger than INT_MAX it leads to a buffer overflow. (Negative shifts are undefined). 439 return -EINVAL; 440 441 if (!pdd->dev->kfd->shared_resources.enable_mes) { 442 r = debug_lock_and_unmap(pdd->dev->dqm); 443 if (r) 444 return r; 445 } 446 447 amdgpu_gfx_off_ctrl(pdd->dev->adev, false); --> 448 pdd->watch_points[watch_id] = pdd->dev->kfd2kgd->clear_address_watch( 449 pdd->dev->adev, 450 watch_id); v2: (as per, Jonathan Kim) - Add early watch_id >= MAX_WATCH_ADDRESSES validation in the set path to match the clear path. - Drop the redundant bounds check in kfd_dbg_owns_dev_watch_id(). Fixes: e0f85f4690d0 ("drm/amdkfd: add debug set and clear address watch points operation") Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Cc: Jonathan Kim <jonathan.kim@amd.com> Cc: Felix Kuehling <felix.kuehling@amd.com> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Christian König <christian.koenig@amd.com> Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com> Reviewed-by: Jonathan Kim <jonathan.kim@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Conflicts: drivers/gpu/drm/amd/amdkfd/kfd_debug.c [Context conflicts.] Signed-off-by: Jiacheng Yu <yujiacheng3@huawei.com> --- drivers/gpu/drm/amd/amdkfd/kfd_debug.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_debug.c b/drivers/gpu/drm/amd/amdkfd/kfd_debug.c index 9c32c64c407f..cd1d92d5cb30 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_debug.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_debug.c @@ -400,27 +400,25 @@ static int kfd_dbg_get_dev_watch_id(struct kfd_process_device *pdd, int *watch_i return -ENOMEM; } -static void kfd_dbg_clear_dev_watch_id(struct kfd_process_device *pdd, int watch_id) +static void kfd_dbg_clear_dev_watch_id(struct kfd_process_device *pdd, u32 watch_id) { spin_lock(&pdd->dev->kfd->watch_points_lock); /* process owns device watch point so safe to clear */ - if ((pdd->alloc_watch_ids >> watch_id) & 0x1) { - pdd->alloc_watch_ids &= ~(0x1 << watch_id); - pdd->dev->kfd->alloc_watch_ids &= ~(0x1 << watch_id); + if (pdd->alloc_watch_ids & BIT(watch_id)) { + pdd->alloc_watch_ids &= ~BIT(watch_id); + pdd->dev->kfd->alloc_watch_ids &= ~BIT(watch_id); } spin_unlock(&pdd->dev->kfd->watch_points_lock); } -static bool kfd_dbg_owns_dev_watch_id(struct kfd_process_device *pdd, int watch_id) +static bool kfd_dbg_owns_dev_watch_id(struct kfd_process_device *pdd, u32 watch_id) { bool owns_watch_id = false; spin_lock(&pdd->dev->kfd->watch_points_lock); - owns_watch_id = watch_id < MAX_WATCH_ADDRESSES && - ((pdd->alloc_watch_ids >> watch_id) & 0x1); - + owns_watch_id = pdd->alloc_watch_ids & BIT(watch_id); spin_unlock(&pdd->dev->kfd->watch_points_lock); return owns_watch_id; @@ -431,6 +429,9 @@ int kfd_dbg_trap_clear_dev_address_watch(struct kfd_process_device *pdd, { int r; + if (watch_id >= MAX_WATCH_ADDRESSES) + return -EINVAL; + if (!kfd_dbg_owns_dev_watch_id(pdd, watch_id)) return -EINVAL; @@ -468,6 +469,9 @@ int kfd_dbg_trap_set_dev_address_watch(struct kfd_process_device *pdd, if (r) return r; + if (*watch_id >= MAX_WATCH_ADDRESSES) + return -EINVAL; + if (!pdd->dev->kfd->shared_resources.enable_mes) { r = debug_lock_and_unmap(pdd->dev->dqm); if (r) { -- 2.34.1