diff options
Diffstat (limited to 'meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/CVE-2022-48689.patch')
| -rw-r--r-- | meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/CVE-2022-48689.patch | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/CVE-2022-48689.patch b/meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/CVE-2022-48689.patch new file mode 100644 index 000000000..136878aaf --- /dev/null +++ b/meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/CVE-2022-48689.patch @@ -0,0 +1,167 @@ +From 3261400639463a853ba2b3be8bd009c2a8089775 Mon Sep 17 00:00:00 2001 +From: Eric Dumazet <edumazet@google.com> +Date: Wed, 31 Aug 2022 23:38:09 +0000 +Subject: [PATCH] tcp: TX zerocopy should not sense pfmemalloc status + +We got a recent syzbot report [1] showing a possible misuse +of pfmemalloc page status in TCP zerocopy paths. + +Indeed, for pages coming from user space or other layers, +using page_is_pfmemalloc() is moot, and possibly could give +false positives. + +There has been attempts to make page_is_pfmemalloc() more robust, +but not using it in the first place in this context is probably better, +removing cpu cycles. + +Note to stable teams : + +You need to backport 84ce071e38a6 ("net: introduce +__skb_fill_page_desc_noacc") as a prereq. + +Race is more probable after commit c07aea3ef4d4 +("mm: add a signature in struct page") because page_is_pfmemalloc() +is now using low order bit from page->lru.next, which can change +more often than page->index. + +Low order bit should never be set for lru.next (when used as an anchor +in LRU list), so KCSAN report is mostly a false positive. + +Backporting to older kernel versions seems not necessary. + +[1] +BUG: KCSAN: data-race in lru_add_fn / tcp_build_frag + +write to 0xffffea0004a1d2c8 of 8 bytes by task 18600 on cpu 0: +__list_add include/linux/list.h:73 [inline] +list_add include/linux/list.h:88 [inline] +lruvec_add_folio include/linux/mm_inline.h:105 [inline] +lru_add_fn+0x440/0x520 mm/swap.c:228 +folio_batch_move_lru+0x1e1/0x2a0 mm/swap.c:246 +folio_batch_add_and_move mm/swap.c:263 [inline] +folio_add_lru+0xf1/0x140 mm/swap.c:490 +filemap_add_folio+0xf8/0x150 mm/filemap.c:948 +__filemap_get_folio+0x510/0x6d0 mm/filemap.c:1981 +pagecache_get_page+0x26/0x190 mm/folio-compat.c:104 +grab_cache_page_write_begin+0x2a/0x30 mm/folio-compat.c:116 +ext4_da_write_begin+0x2dd/0x5f0 fs/ext4/inode.c:2988 +generic_perform_write+0x1d4/0x3f0 mm/filemap.c:3738 +ext4_buffered_write_iter+0x235/0x3e0 fs/ext4/file.c:270 +ext4_file_write_iter+0x2e3/0x1210 +call_write_iter include/linux/fs.h:2187 [inline] +new_sync_write fs/read_write.c:491 [inline] +vfs_write+0x468/0x760 fs/read_write.c:578 +ksys_write+0xe8/0x1a0 fs/read_write.c:631 +__do_sys_write fs/read_write.c:643 [inline] +__se_sys_write fs/read_write.c:640 [inline] +__x64_sys_write+0x3e/0x50 fs/read_write.c:640 +do_syscall_x64 arch/x86/entry/common.c:50 [inline] +do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 +entry_SYSCALL_64_after_hwframe+0x63/0xcd + +read to 0xffffea0004a1d2c8 of 8 bytes by task 18611 on cpu 1: +page_is_pfmemalloc include/linux/mm.h:1740 [inline] +__skb_fill_page_desc include/linux/skbuff.h:2422 [inline] +skb_fill_page_desc include/linux/skbuff.h:2443 [inline] +tcp_build_frag+0x613/0xb20 net/ipv4/tcp.c:1018 +do_tcp_sendpages+0x3e8/0xaf0 net/ipv4/tcp.c:1075 +tcp_sendpage_locked net/ipv4/tcp.c:1140 [inline] +tcp_sendpage+0x89/0xb0 net/ipv4/tcp.c:1150 +inet_sendpage+0x7f/0xc0 net/ipv4/af_inet.c:833 +kernel_sendpage+0x184/0x300 net/socket.c:3561 +sock_sendpage+0x5a/0x70 net/socket.c:1054 +pipe_to_sendpage+0x128/0x160 fs/splice.c:361 +splice_from_pipe_feed fs/splice.c:415 [inline] +__splice_from_pipe+0x222/0x4d0 fs/splice.c:559 +splice_from_pipe fs/splice.c:594 [inline] +generic_splice_sendpage+0x89/0xc0 fs/splice.c:743 +do_splice_from fs/splice.c:764 [inline] +direct_splice_actor+0x80/0xa0 fs/splice.c:931 +splice_direct_to_actor+0x305/0x620 fs/splice.c:886 +do_splice_direct+0xfb/0x180 fs/splice.c:974 +do_sendfile+0x3bf/0x910 fs/read_write.c:1249 +__do_sys_sendfile64 fs/read_write.c:1317 [inline] +__se_sys_sendfile64 fs/read_write.c:1303 [inline] +__x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1303 +do_syscall_x64 arch/x86/entry/common.c:50 [inline] +do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 +entry_SYSCALL_64_after_hwframe+0x63/0xcd + +value changed: 0x0000000000000000 -> 0xffffea0004a1d288 + +Reported by Kernel Concurrency Sanitizer on: +CPU: 1 PID: 18611 Comm: syz-executor.4 Not tainted 6.0.0-rc2-syzkaller-00248-ge022620b5d05-dirty #0 +Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 + +Fixes: c07aea3ef4d4 ("mm: add a signature in struct page") +Reported-by: syzbot <syzkaller@googlegroups.com> +Signed-off-by: Eric Dumazet <edumazet@google.com> +Cc: Shakeel Butt <shakeelb@google.com> +Reviewed-by: Shakeel Butt <shakeelb@google.com> +Signed-off-by: David S. Miller <davem@davemloft.net> +--- + include/linux/skbuff.h | 20 ++++++++++++++++++++ + net/core/datagram.c | 2 +- + net/ipv4/tcp.c | 2 +- + 3 files changed, 22 insertions(+), 2 deletions(-) + +diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h +index 841e2f0f5240..051843e918c8 100644 +--- a/include/linux/skbuff.h ++++ b/include/linux/skbuff.h +@@ -2211,6 +2211,26 @@ static inline void skb_fill_page_desc(struct sk_buff *skb, int i, + skb_shinfo(skb)->nr_frags = i + 1; + } + ++/** ++ * skb_fill_page_desc_noacc - initialise a paged fragment in an skb ++ * @skb: buffer containing fragment to be initialised ++ * @i: paged fragment index to initialise ++ * @page: the page to use for this fragment ++ * @off: the offset to the data with @page ++ * @size: the length of the data ++ * ++ * Variant of skb_fill_page_desc() which does not deal with ++ * pfmemalloc, if page is not owned by us. ++ */ ++static inline void skb_fill_page_desc_noacc(struct sk_buff *skb, int i, ++ struct page *page, int off, ++ int size) ++{ ++ struct skb_shared_info *shinfo = skb_shinfo(skb); ++ ++ shinfo->nr_frags = i + 1; ++} ++ + void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off, + int size, unsigned int truesize); + +diff --git a/net/core/datagram.c b/net/core/datagram.c +index 15ab9ffb27fe..28e5f921dcaf 100644 +--- a/net/core/datagram.c ++++ b/net/core/datagram.c +@@ -677,7 +677,7 @@ int __zerocopy_sg_from_iter(struct sock *sk, struct sk_buff *skb, + page_ref_sub(last_head, refs); + refs = 0; + } +- skb_fill_page_desc(skb, frag++, head, start, size); ++ skb_fill_page_desc_noacc(skb, frag++, head, start, size); + } + if (refs) + page_ref_sub(last_head, refs); +diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c +index c86d27d653be..d066d780010d 100644 +--- a/net/ipv4/tcp.c ++++ b/net/ipv4/tcp.c +@@ -1002,7 +1002,7 @@ struct sk_buff *tcp_build_frag(struct sock *sk, int size_goal, int flags, + skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); + } else { + get_page(page); +- skb_fill_page_desc(skb, i, page, offset, copy); ++ skb_fill_page_desc_noacc(skb, i, page, offset, copy); + } + + if (!(flags & MSG_NO_SHARED_FRAGS)) +-- +2.25.1 + |