From: Jialiang Wang wangjialiang0806@163.com
commit 02e1a114fdb71e59ee6770294166c30d437bf86a upstream.
area_cache_get() is used to distribute cache->area and set cache->id, and if cache->id is not 0 and cache->area->kref refcount is 0, it will release the cache->area by nfp_cpp_area_release(). area_cache_get() set cache->id before cpp->op->area_init() and nfp_cpp_area_acquire().
But if area_init() or nfp_cpp_area_acquire() fails, the cache->id is is already set but the refcount is not increased as expected. At this time, calling the nfp_cpp_area_release() will cause use-after-free.
To avoid the use-after-free, set cache->id after area_init() and nfp_cpp_area_acquire() complete successfully.
Note: This vulnerability is triggerable by providing emulated device equipped with specified configuration.
BUG: KASAN: use-after-free in nfp6000_area_init (drivers/net/ethernet/netronome/nfp/nfpcore/nfp6000_pcie.c:760) Write of size 4 at addr ffff888005b7f4a0 by task swapper/0/1
Call Trace: <TASK> nfp6000_area_init (drivers/net/ethernet/netronome/nfp/nfpcore/nfp6000_pcie.c:760) area_cache_get.constprop.8 (drivers/net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.c:884)
Allocated by task 1: nfp_cpp_area_alloc_with_name (drivers/net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.c:303) nfp_cpp_area_cache_add (drivers/net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.c:802) nfp6000_init (drivers/net/ethernet/netronome/nfp/nfpcore/nfp6000_pcie.c:1230) nfp_cpp_from_operations (drivers/net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.c:1215) nfp_pci_probe (drivers/net/ethernet/netronome/nfp/nfp_main.c:744)
Freed by task 1: kfree (mm/slub.c:4562) area_cache_get.constprop.8 (drivers/net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.c:873) nfp_cpp_read (drivers/net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.c:924 drivers/net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.c:973) nfp_cpp_readl (drivers/net/ethernet/netronome/nfp/nfpcore/nfp_cpplib.c:48)
Signed-off-by: Jialiang Wang wangjialiang0806@163.com Reviewed-by: Yinjun Zhang yinjun.zhang@corigine.com Acked-by: Simon Horman simon.horman@corigine.com Link: https://lore.kernel.org/r/20220810073057.4032-1-wangjialiang0806@163.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.c +++ b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.c @@ -874,7 +874,6 @@ area_cache_get(struct nfp_cpp *cpp, u32 }
/* Adjust the start address to be cache size aligned */ - cache->id = id; cache->addr = addr & ~(u64)(cache->size - 1);
/* Re-init to the new ID and address */ @@ -894,6 +893,8 @@ area_cache_get(struct nfp_cpp *cpp, u32 return NULL; }
+ cache->id = id; + exit: /* Adjust offset */ *offset = addr - cache->addr;