From d94c3fa54a99cbd2560d9f7c2f3c0edd50d1f534 Mon Sep 17 00:00:00 2001 From: Thomas Perale Date: Wed, 12 Aug 2026 14:34:48 +0200 Subject: [PATCH] package/util-linux: backport patch CVE-2026-13595 - CVE-2026-13595: A flaw was found in the libblkid library of util-linux. During nested partition probing, the BSD, Minix, Solaris x86, and UnixWare partition probers cache a raw pointer to a parent partition entry in a dynamically allocated array. When subsequent partition additions cause the array to be reallocated, this pointer becomes stale, leading to a heap use-after-free read. An attacker who can present a crafted block device image (for example, via USB insertion or a loop-mounted disk image) can trigger this flaw without user interaction, as libblkid is invoked automatically by udev/udisks as root on block-device hot-plug events. This could lead to limited information disclosure or denial of service. For more information, see: - https://www.cve.org/CVERecord?id=CVE-2026-13595 - https://github.com/util-linux/util-linux/commit/c0186f14fbdb02f64c8e0ba701ce727ea764ff4c Signed-off-by: Thomas Perale Signed-off-by: Titouan Christophe --- package/util-linux/0015-CVE-2026-13595.patch | 145 +++++++++++++++++++ package/util-linux/util-linux.mk | 3 + 2 files changed, 148 insertions(+) create mode 100644 package/util-linux/0015-CVE-2026-13595.patch diff --git a/package/util-linux/0015-CVE-2026-13595.patch b/package/util-linux/0015-CVE-2026-13595.patch new file mode 100644 index 0000000000..7547a20137 --- /dev/null +++ b/package/util-linux/0015-CVE-2026-13595.patch @@ -0,0 +1,145 @@ +From c0186f14fbdb02f64c8e0ba701ce727ea764ff4c Mon Sep 17 00:00:00 2001 +From: Karel Zak +Date: Thu, 7 May 2026 12:50:48 +0200 +Subject: [PATCH] libblkid: fix use-after-free in nested partition probing + +The partitions list stores partitions in a contiguous array grown by +reallocarray(). When the array is reallocated to a new address, all +existing blkid_partition pointers (tab->parent, ls->next_parent, local +parent variables in nested probers) become dangling. + +Fix this by changing the storage from an array of structs to an array +of pointers, where each partition is individually allocated via +calloc(). This makes all blkid_partition pointers stable across +reallocations -- only the pointer array itself may move, which is +harmless since no code caches pointers into the pointer array. + +This eliminates the need for callers to re-fetch parent pointers after +every blkid_partlist_add_partition() call. + +Reported-by: Thai Duong +Signed-off-by: Karel Zak +CVE: CVE-2026-13595 +Upstream: https://github.com/util-linux/util-linux/commit/c0186f14fbdb02f64c8e0ba701ce727ea764ff4c +Signed-off-by: Thomas Perale +--- + libblkid/src/partitions/partitions.c | 34 +++++++++++++++++----------- + 1 file changed, 21 insertions(+), 13 deletions(-) + +diff --git a/libblkid/src/partitions/partitions.c b/libblkid/src/partitions/partitions.c +index f95fe898f33..a428c6d6c16 100644 +--- a/libblkid/src/partitions/partitions.c ++++ b/libblkid/src/partitions/partitions.c +@@ -197,7 +197,7 @@ struct blkid_struct_partlist { + + int nparts; /* number of partitions */ + int nparts_max; /* max.number of partitions */ +- blkid_partition parts; /* array of partitions */ ++ blkid_partition *parts; /* array of pointers to partitions */ + + struct list_head l_tabs; /* list of partition tables */ + }; +@@ -356,13 +356,16 @@ static void reset_partlist(blkid_partlist ls) + free_parttables(ls); + + if (ls->next_partno) { +- /* already initialized - reset */ +- int tmp_nparts = ls->nparts_max; +- blkid_partition tmp_parts = ls->parts; ++ /* already initialized - free individually allocated partitions */ ++ int i, tmp_nparts_max = ls->nparts_max; ++ blkid_partition *tmp_parts = ls->parts; ++ ++ for (i = 0; i < ls->nparts; i++) ++ free(ls->parts[i]); + + memset(ls, 0, sizeof(struct blkid_struct_partlist)); + +- ls->nparts_max = tmp_nparts; ++ ls->nparts_max = tmp_nparts_max; + ls->parts = tmp_parts; + } + +@@ -397,6 +400,7 @@ static void partitions_free_data(blkid_probe pr __attribute__((__unused__)), + void *data) + { + blkid_partlist ls = (blkid_partlist) data; ++ int i; + + if (!ls) + return; +@@ -404,6 +408,8 @@ static void partitions_free_data(blkid_probe pr __attribute__((__unused__)), + free_parttables(ls); + + /* deallocate partitions and partlist */ ++ for (i = 0; i < ls->nparts; i++) ++ free(ls->parts[i]); + free(ls->parts); + free(ls); + } +@@ -437,15 +443,17 @@ static blkid_partition new_partition(blkid_partlist ls, blkid_parttable tab) + * generic Linux machine -- let start with 32 partitions. + */ + void *tmp = reallocarray(ls->parts, ls->nparts_max + 32, +- sizeof(struct blkid_struct_partition)); ++ sizeof(blkid_partition)); + if (!tmp) + return NULL; + ls->parts = tmp; + ls->nparts_max += 32; + } + +- par = &ls->parts[ls->nparts++]; +- memset(par, 0, sizeof(struct blkid_struct_partition)); ++ par = calloc(1, sizeof(struct blkid_struct_partition)); ++ if (!par) ++ return NULL; ++ ls->parts[ls->nparts++] = par; + + ref_parttable(tab); + par->tab = tab; +@@ -850,7 +858,7 @@ int blkid_probe_is_covered_by_pt(blkid_probe pr, + + /* check if the partition table fits into the device */ + for (i = 0; i < nparts; i++) { +- blkid_partition par = &ls->parts[i]; ++ blkid_partition par = ls->parts[i]; + + if (par->start + par->size > (pr->size >> 9)) { + DBG(LOWPROBE, ul_debug("partition #%d overflows " +@@ -862,7 +870,7 @@ int blkid_probe_is_covered_by_pt(blkid_probe pr, + + /* check if the requested area is covered by PT */ + for (i = 0; i < nparts; i++) { +- blkid_partition par = &ls->parts[i]; ++ blkid_partition par = ls->parts[i]; + + if (start >= par->start && end <= par->start + par->size) { + rc = 1; +@@ -961,7 +969,7 @@ blkid_partition blkid_partlist_get_partition(blkid_partlist ls, int n) + if (n < 0 || n >= ls->nparts) + return NULL; + +- return &ls->parts[n]; ++ return ls->parts[n]; + } + + blkid_partition blkid_partlist_get_partition_by_start(blkid_partlist ls, uint64_t start) +@@ -1073,7 +1081,7 @@ blkid_partition blkid_partlist_devno_to_partition(blkid_partlist ls, dev_t devno + * and an entry in partition table. + */ + for (i = 0; i < ls->nparts; i++) { +- blkid_partition par = &ls->parts[i]; ++ blkid_partition par = ls->parts[i]; + + if (partno != blkid_partition_get_partno(par)) + continue; +@@ -1089,7 +1097,7 @@ blkid_partition blkid_partlist_devno_to_partition(blkid_partlist ls, dev_t devno + DBG(LOWPROBE, ul_debug("searching by offset/size")); + + for (i = 0; i < ls->nparts; i++) { +- blkid_partition par = &ls->parts[i]; ++ blkid_partition par = ls->parts[i]; + + if ((uint64_t)blkid_partition_get_start(par) == start && + (uint64_t)blkid_partition_get_size(par) == size) diff --git a/package/util-linux/util-linux.mk b/package/util-linux/util-linux.mk index b5364b710b..9e56894611 100644 --- a/package/util-linux/util-linux.mk +++ b/package/util-linux/util-linux.mk @@ -54,6 +54,9 @@ UTIL_LINUX_IGNORE_CVES += CVE-2026-53613 # 0013-CVE-2026-53614.patch UTIL_LINUX_IGNORE_CVES += CVE-2026-53614 +# 0015-CVE-2026-13595.patch +UTIL_LINUX_IGNORE_CVES += CVE-2026-13595 + UTIL_LINUX_INSTALL_STAGING = YES UTIL_LINUX_DEPENDENCIES = \ host-pkgconf \