diff options
| author | Jason Gunthorpe <jgg@nvidia.com> | 2025-05-14 09:48:55 -0300 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2025-05-16 14:29:16 +0200 |
| commit | 5e2ff240b31a37226260587e33707efc3c41e451 (patch) | |
| tree | e7b529a34d92754c2d64cde87d52512b2d8e8b6b | |
| parent | e436576b0231542f6f233279f0972989232575a8 (diff) | |
| download | linux-core.tar.gz | |
iommu: Clear the freelist after iommu_put_pages_list()core
The commit below reworked how iommu_put_pages_list() worked to not do
list_del() on every entry. This was done expecting all the callers to
already re-init the list so doing a per-item deletion is not
efficient.
It was missed that fq_ring_free_locked() re-uses its list after calling
iommu_put_pages_list() and so the leftover list reaches free'd struct
pages and will crash or WARN/BUG/etc.
Reinit the list to empty in fq_ring_free_locked() after calling
iommu_put_pages_list().
Audit to see if any other callers of iommu_put_pages_list() need the list
to be empty:
- iommu_dma_free_fq_single() and iommu_dma_free_fq_percpu() immediately
frees the memory
- iommu_v1_map_pages(), v1_free_pgtable(), domain_exit(),
riscv_iommu_map_pages() uses a stack variable which goes out of scope
- intel_iommu_tlb_sync() uses a gather in a iotlb_sync() callback, the
caller re-inits the gather
Fixes: 13f43d7cf3e0 ("iommu/pages: Formalize the freelist API")
Reported-by: Borah, Chaitanya Kumar <chaitanya.kumar.borah@intel.com>
Closes: https://lore.kernel.org/r/SJ1PR11MB61292CE72D7BE06B8810021CB997A@SJ1PR11MB6129.namprd11.prod.outlook.com
Tested-by: Borah, Chaitanya Kumar <chaitanya.kumar.borah@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/0-v1-7d4dfa6140f7+11f04-iommu_freelist_init_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
| -rw-r--r-- | drivers/iommu/dma-iommu.c | 2 | ||||
| -rw-r--r-- | drivers/iommu/iommu-pages.c | 4 |
2 files changed, 5 insertions, 1 deletions
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 0af1ab36283cba..7d2b51a890c75a 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -154,6 +154,8 @@ static void fq_ring_free_locked(struct iommu_dma_cookie *cookie, struct iova_fq fq->entries[idx].iova_pfn, fq->entries[idx].pages); + fq->entries[idx].freelist = + IOMMU_PAGES_LIST_INIT(fq->entries[idx].freelist); fq->head = (fq->head + 1) & fq->mod_mask; } } diff --git a/drivers/iommu/iommu-pages.c b/drivers/iommu/iommu-pages.c index 4cc77fddfeeb47..238c09e5166b4d 100644 --- a/drivers/iommu/iommu-pages.c +++ b/drivers/iommu/iommu-pages.c @@ -105,7 +105,9 @@ EXPORT_SYMBOL_GPL(iommu_free_pages); * iommu_put_pages_list - free a list of pages. * @list: The list of pages to be freed * - * Frees a list of pages allocated by iommu_alloc_pages_node_sz(). + * Frees a list of pages allocated by iommu_alloc_pages_node_sz(). On return the + * passed list is invalid, the caller must use IOMMU_PAGES_LIST_INIT to reinit + * the list if it expects to use it again. */ void iommu_put_pages_list(struct iommu_pages_list *list) { |