From: Greg Kroah-Hartman Date: Thu, 13 Aug 2026 14:10:52 +0000 (+0900) Subject: 7.1-stable patches X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=6c833ac71aca397d2ec1374a14f6841e56d7e772;p=thirdparty%2Fkernel%2Fstable-queue.git 7.1-stable patches added patches: ima-fix-out-of-bounds-read-in-xattr_verify.patch --- diff --git a/queue-7.1/ima-fix-out-of-bounds-read-in-xattr_verify.patch b/queue-7.1/ima-fix-out-of-bounds-read-in-xattr_verify.patch new file mode 100644 index 0000000000..558e872169 --- /dev/null +++ b/queue-7.1/ima-fix-out-of-bounds-read-in-xattr_verify.patch @@ -0,0 +1,59 @@ +From 5ff232d31106f45ac87c3b64e1d35a0667777797 Mon Sep 17 00:00:00 2001 +From: Lincoln Wallace +Date: Mon, 3 Aug 2026 10:50:21 -0300 +Subject: ima: fix out-of-bounds read in xattr_verify() + +From: Lincoln Wallace + +commit 5ff232d31106f45ac87c3b64e1d35a0667777797 upstream. + +The digest-length check in xattr_verify() mixes int and size_t: + + if (xattr_len - sizeof(xattr_value->type) - hash_start >= + iint->ima_hash->length) + +sizeof() yields size_t, so the usual arithmetic conversions promote +the whole left-hand side to unsigned 64-bit before the subtraction +runs. For a truncated xattr this underflows instead of going negative: +a 1-byte IMA_XATTR_DIGEST_NG xattr (xattr_len == 1, hash_start == 1) +turns "1 - 1 - 1" into SIZE_MAX, which is trivially >= ima_hash->length. +The check then passes and the following memcmp() reads +iint->ima_hash->length bytes starting past the end of the buffer +vfs_getxattr_alloc() allocated for it. + +Nothing upstream clamps xattr_len back into a safe range first: +ima_get_hash_algo() only special-cases xattr_len < 2 to pick a default +algorithm, and evm_verifyxattr() returns INTEGRITY_UNKNOWN rather than +failing when no HMAC key is loaded, so a truncated security.ima value +reaches the length check as-is. + +Rewrite the comparison so every operand stays a signed int and no +implicit conversion to size_t can occur. + +Fixes: 3ea7a56067e6 ("ima: provide hash algo info in the xattr") +Cc: stable@vger.kernel.org +Signed-off-by: Lincoln Wallace +Signed-off-by: Mimi Zohar +Signed-off-by: Greg Kroah-Hartman +--- + security/integrity/ima/ima_appraise.c | 9 +++++++-- + 1 file changed, 7 insertions(+), 2 deletions(-) + +--- a/security/integrity/ima/ima_appraise.c ++++ b/security/integrity/ima/ima_appraise.c +@@ -269,8 +269,13 @@ static int xattr_verify(enum ima_hooks f + } else { + set_bit(IMA_DIGSIG, &iint->atomic_flags); + } +- if (xattr_len - sizeof(xattr_value->type) - hash_start >= +- iint->ima_hash->length) ++ /* ++ * Use addition, not subtraction: sizeof() forces unsigned ++ * math and a short xattr_len would wrap around, bypassing ++ * this bounds check. ++ */ ++ if (xattr_len >= (int)sizeof(xattr_value->type) + hash_start + ++ (int)iint->ima_hash->length) + /* + * xattr length may be longer. md5 hash in previous + * version occupied 20 bytes in xattr, instead of 16 diff --git a/queue-7.1/series b/queue-7.1/series index aae3eadb78..f4f5939851 100644 --- a/queue-7.1/series +++ b/queue-7.1/series @@ -140,3 +140,4 @@ vt-stabilize-tty-reference-in-kbd_keycode-with-tty_port_tty_get.patch mm-fix-incorrect-flush-address-in-direct-page-table-reclaim.patch input-evdev-fix-information-leak-in-evdev_pass_values.patch mm-vmalloc-acquire-init_mm-lock-on-huge-vmap-to-avoid-ptdump-uaf.patch +ima-fix-out-of-bounds-read-in-xattr_verify.patch