From: Hauke Mehrtens Date: Sun, 22 Dec 2024 15:41:11 +0000 (+0100) Subject: kernel: generic: netfilter: nft_set_hash: unaligned atomic read on struct nft_set_ext X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=4585d5abd9b77fa9ef794407c5dedcbc4001c869;p=openwrt%2Fstaging%2Fstintel.git kernel: generic: netfilter: nft_set_hash: unaligned atomic read on struct nft_set_ext Fix kernel panic on some 64 bit architectures. This patch is pending upstream. https://patchwork.ozlabs.org/project/netfilter-devel/patch/20241222100239.336289-1-pablo@netfilter.org/ Fixes: https://github.com/openwrt/openwrt/issues/17336 Link: https://github.com/openwrt/openwrt/pull/17340 Signed-off-by: Hauke Mehrtens --- diff --git a/target/linux/generic/pending-6.6/605-netfilter-nft_set_hash-unaligned-atomic-read-on-stru.patch b/target/linux/generic/pending-6.6/605-netfilter-nft_set_hash-unaligned-atomic-read-on-stru.patch new file mode 100644 index 0000000000..61e163293e --- /dev/null +++ b/target/linux/generic/pending-6.6/605-netfilter-nft_set_hash-unaligned-atomic-read-on-stru.patch @@ -0,0 +1,87 @@ +From 113fb8a8d1f27156f58b27ce0fc02af9b3705bf7 Mon Sep 17 00:00:00 2001 +From: Pablo Neira Ayuso +Date: Sun, 22 Dec 2024 11:02:39 +0100 +Subject: [PATCH] netfilter: nft_set_hash: unaligned atomic read on struct + nft_set_ext + +Access to genmask field in struct nft_set_ext results in unaligned +atomic read: + +[ 72.130109] Unable to handle kernel paging request at virtual address ffff0000c2bb708c +[ 72.131036] Mem abort info: +[ 72.131213] ESR = 0x0000000096000021 +[ 72.131446] EC = 0x25: DABT (current EL), IL = 32 bits +[ 72.132209] SET = 0, FnV = 0 +[ 72.133216] EA = 0, S1PTW = 0 +[ 72.134080] FSC = 0x21: alignment fault +[ 72.135593] Data abort info: +[ 72.137194] ISV = 0, ISS = 0x00000021, ISS2 = 0x00000000 +[ 72.142351] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 +[ 72.145989] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 +[ 72.150115] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000237d27000 +[ 72.154893] [ffff0000c2bb708c] pgd=0000000000000000, p4d=180000023ffff403, pud=180000023f84b403, pmd=180000023f835403, ++pte=0068000102bb7707 +[ 72.163021] Internal error: Oops: 0000000096000021 [#1] SMP +[...] +[ 72.170041] CPU: 7 UID: 0 PID: 54 Comm: kworker/7:0 Tainted: G E 6.13.0-rc3+ #2 +[ 72.170509] Tainted: [E]=UNSIGNED_MODULE +[ 72.170720] Hardware name: QEMU QEMU Virtual Machine, BIOS edk2-stable202302-for-qemu 03/01/2023 +[ 72.171192] Workqueue: events_power_efficient nft_rhash_gc [nf_tables] +[ 72.171552] pstate: 21400005 (nzCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--) +[ 72.171915] pc : nft_rhash_gc+0x200/0x2d8 [nf_tables] +[ 72.172166] lr : nft_rhash_gc+0x128/0x2d8 [nf_tables] +[ 72.172546] sp : ffff800081f2bce0 +[ 72.172724] x29: ffff800081f2bd40 x28: ffff0000c2bb708c x27: 0000000000000038 +[ 72.173078] x26: ffff0000c6780ef0 x25: ffff0000c643df00 x24: ffff0000c6778f78 +[ 72.173431] x23: 000000000000001a x22: ffff0000c4b1f000 x21: ffff0000c6780f78 +[ 72.173782] x20: ffff0000c2bb70dc x19: ffff0000c2bb7080 x18: 0000000000000000 +[ 72.174135] x17: ffff0000c0a4e1c0 x16: 0000000000003000 x15: 0000ac26d173b978 +[ 72.174485] x14: ffffffffffffffff x13: 0000000000000030 x12: ffff0000c6780ef0 +[ 72.174841] x11: 0000000000000000 x10: ffff800081f2bcf8 x9 : ffff0000c3000000 +[ 72.175193] x8 : 00000000000004be x7 : 0000000000000000 x6 : 0000000000000000 +[ 72.175544] x5 : 0000000000000040 x4 : ffff0000c3000010 x3 : 0000000000000000 +[ 72.175871] x2 : 0000000000003a98 x1 : ffff0000c2bb708c x0 : 0000000000000004 +[ 72.176207] Call trace: +[ 72.176316] nft_rhash_gc+0x200/0x2d8 [nf_tables] (P) +[ 72.176653] process_one_work+0x178/0x3d0 +[ 72.176831] worker_thread+0x200/0x3f0 +[ 72.176995] kthread+0xe8/0xf8 +[ 72.177130] ret_from_fork+0x10/0x20 +[ 72.177289] Code: 54fff984 d503201f d2800080 91003261 (f820303f) +[ 72.177557] ---[ end trace 0000000000000000 ]--- + +Align struct nft_set_ext to word size to address this and +documentation it. + +pahole reports that this increases the size of elements for rhash and +pipapo in 8 bytes on x86_64. + +Fixes: 7ffc7481153b ("netfilter: nft_set_hash: skip duplicated elements pending gc run") +Signed-off-by: Pablo Neira Ayuso +--- + include/net/netfilter/nf_tables.h | 7 +++++-- + 1 file changed, 5 insertions(+), 2 deletions(-) + +--- a/include/net/netfilter/nf_tables.h ++++ b/include/net/netfilter/nf_tables.h +@@ -721,15 +721,18 @@ struct nft_set_ext_tmpl { + /** + * struct nft_set_ext - set extensions + * +- * @genmask: generation mask ++ * @genmask: generation mask, but also flags (see NFT_SET_ELEM_DEAD_BIT) + * @offset: offsets of individual extension types + * @data: beginning of extension data ++ * ++ * This structure must be aligned to word size, otherwise atomic bitops ++ * on genmask field can cause aligment failure on some archs. + */ + struct nft_set_ext { + u8 genmask; + u8 offset[NFT_SET_EXT_NUM]; + char data[]; +-}; ++} __aligned(BITS_PER_LONG / 8); + + static inline void nft_set_ext_prepare(struct nft_set_ext_tmpl *tmpl) + {