[scarthgap][PATCH v2 1/7] libpcap: Fix CVE-2026-0799

[Jaipaul Cheernam <jaipaul.cheernam@est.tech>]

NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-0799
Upstream-commit: https://github.com/the-tcpdump-group/libpcap/commit/48e8960a7108e9e828f9d7bdc7e97bdab841aec7

Signed-off-by: Jaipaul Cheernam <jaipaul.cheernam@est.tech>
---
 .../libpcap/libpcap/01-CVE-2026-0799.patch    | 67 +++++++++++++++++++
 .../libpcap/libpcap_1.10.4.bb                 |  1 +
 2 files changed, 68 insertions(+)
 create mode 100644 meta/recipes-connectivity/libpcap/libpcap/01-CVE-2026-0799.patch

diff --git a/meta/recipes-connectivity/libpcap/libpcap/01-CVE-2026-0799.patch b/meta/recipes-connectivity/libpcap/libpcap/01-CVE-2026-0799.patch
new file mode 100644
index 0000000000..a4dfea4236
--- /dev/null
+++ b/meta/recipes-connectivity/libpcap/libpcap/01-CVE-2026-0799.patch
@@ -0,0 +1,67 @@
+From 48e8960a7108e9e828f9d7bdc7e97bdab841aec7 Mon Sep 17 00:00:00 2001
+From: Denis Ovsienko <denis@ovsienko.info>
+Date: Thu, 30 Jul 2026 13:33:41 +0100
+Subject: [PATCH] CVE-2026-0799: Access M[] safely in the BPF interpreter.
+
+Include Security identified and reported this problem as a potential
+vulnerability in 2018 (case reference "I7").  Their work was sponsored
+by Mozilla under the Secure Open Source program.  The vulnerability has
+been independently confirmed only recently.
+
+The current revision of pcapint_filter_with_aux_data() can, but does not
+check whether a scratch memory register index is valid in the "ld M[k]",
+"ldx M[k]", "st M[k]" and "stx M[k]" BPF instructions, and assumes this
+is always the case.  This holds for programs that have been generated or
+validated by libpcap.
+
+However, this does not necessarily hold for programs that come via
+pcap_offline_filter() or [deprecated] bpf_filter() from an external
+source and have not been explicitly validated.  If the interpreter
+executes such a program with an invalid index, it will read/write the
+process memory at arbitrary locations starting at the current stack
+frame.  Depending on the address, the memory layout and the OS, this can
+result in stack buffer overflow, SIGSEGV, SIGBUS or other effects.  To
+fix this, in the interpreter reject the packet if the index is invalid.
+
+(backported from commit 569f8fd3524192acbabf93c9cd704471bb38f84a)
+
+(cherry picked from commit 48e8960a7108e9e828f9d7bdc7e97bdab841aec7)
+
+Notes on backporting to 1.10.4:
+ - The upstream CHANGES/changelog hunk is not backported.
+
+Upstream-Status: Backport [https://github.com/the-tcpdump-group/libpcap/commit/48e8960a7108e9e828f9d7bdc7e97bdab841aec7]
+CVE: CVE-2026-0799
+Signed-off-by: Jaipaul Cheernam <jaipaul.cheernam@est.tech>
+---
+diff --git a/bpf_filter.c b/bpf_filter.c
+index 8691d0d1..fa82d1d0 100644
+--- a/bpf_filter.c
++++ b/bpf_filter.c
+@@ -219,18 +219,26 @@ DIAG_ON_DEFAULT_ONLY_SWITCH
+ 			continue;
+ 
+ 		case BPF_LD|BPF_MEM:
++			if (pc->k >= BPF_MEMWORDS)
++				return 0;
+ 			A = mem[pc->k];
+ 			continue;
+ 
+ 		case BPF_LDX|BPF_MEM:
++			if (pc->k >= BPF_MEMWORDS)
++				return 0;
+ 			X = mem[pc->k];
+ 			continue;
+ 
+ 		case BPF_ST:
++			if (pc->k >= BPF_MEMWORDS)
++				return 0;
+ 			mem[pc->k] = A;
+ 			continue;
+ 
+ 		case BPF_STX:
++			if (pc->k >= BPF_MEMWORDS)
++				return 0;
+ 			mem[pc->k] = X;
+ 			continue;
+ 
diff --git a/meta/recipes-connectivity/libpcap/libpcap_1.10.4.bb b/meta/recipes-connectivity/libpcap/libpcap_1.10.4.bb
index ee7d7540f6..692fdf606c 100644
--- a/meta/recipes-connectivity/libpcap/libpcap_1.10.4.bb
+++ b/meta/recipes-connectivity/libpcap/libpcap_1.10.4.bb
@@ -17,6 +17,7 @@ SRC_URI = "https://www.tcpdump.org/release/${BP}.tar.gz \
            file://CVE-2025-11961-01.patch \
            file://CVE-2025-11961-02.patch \
            file://CVE-2025-11964.patch \
+           file://01-CVE-2026-0799.patch \
           "
 
 SRC_URI[sha256sum] = "ed19a0383fad72e3ad435fd239d7cd80d64916b87269550159d20e47160ebe5f"