Dear Stable,
[NB: Re-poking Stable with the correct contact address this time! :)]
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 (/home/user/Kernel/v5.19 /x86_64/src/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 (/home/user/Kernel/v5.19/x86_64/src/drivers/net /ethernet/netronome/nfp/nfpcore/nfp6000_pcie.c:760) area_cache_get.constprop.8 (/home/user/Kernel/v5.19/x86_64/src/drivers /net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.c:884)
Allocated by task 1: nfp_cpp_area_alloc_with_name (/home/user/Kernel/v5.19/x86_64/src/drivers /net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.c:303) nfp_cpp_area_cache_add (/home/user/Kernel/v5.19/x86_64/src/drivers/net /ethernet/netronome/nfp/nfpcore/nfp_cppcore.c:802) nfp6000_init (/home/user/Kernel/v5.19/x86_64/src/drivers/net/ethernet /netronome/nfp/nfpcore/nfp6000_pcie.c:1230) nfp_cpp_from_operations (/home/user/Kernel/v5.19/x86_64/src/drivers/net /ethernet/netronome/nfp/nfpcore/nfp_cppcore.c:1215) nfp_pci_probe (/home/user/Kernel/v5.19/x86_64/src/drivers/net/ethernet /netronome/nfp/nfp_main.c:744)
Freed by task 1: kfree (/home/user/Kernel/v5.19/x86_64/src/mm/slub.c:4562) area_cache_get.constprop.8 (/home/user/Kernel/v5.19/x86_64/src/drivers /net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.c:873) nfp_cpp_read (/home/user/Kernel/v5.19/x86_64/src/drivers/net/ethernet /netronome/nfp/nfpcore/nfp_cppcore.c:924 /home/user/Kernel/v5.19/x86_64 /src/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.c:973) nfp_cpp_readl (/home/user/Kernel/v5.19/x86_64/src/drivers/net/ethernet /netronome/nfp/nfpcore/nfp_cpplib.c:48)
Signed-off-by: Jialiang Wang wangjialiang0806@163.com
Any reason why this doesn't have a Fixes: tag applied and/or didn't get sent to Stable?
Looks as if this needs to go back as far as v4.19.
Fixes: 4cb584e0ee7df ("nfp: add CPP access core")
commit 02e1a114fdb71e59ee6770294166c30d437bf86a upstream.
Would you be able to take this with the information provided please?