linux/tools
Danish Khateeb 2111eb4273 tools/nolibc: check for overflow in malloc()
malloc() adds the size of its header to the requested size without
checking for overflow. For a size within the header size of SIZE_MAX,
the sum wraps around to a few bytes, and malloc() returns a single page
instead of NULL.

calloc() checks its multiplication for overflow, but then passes the
product to malloc(), so calloc(SIZE_MAX, 1) returns a single page too.
So does realloc(ptr, SIZE_MAX).

Such a size is usually a bug in the caller, for instance a length of -1
used as a size_t, and returning a page instead of NULL can turn it into
a heap overflow.

Fail with ENOMEM when adding the header overflows, as glibc does for
sizes this large.

Fixes: 0e0ff63840 ("tools/nolibc/stdlib: Implement `malloc()`, `calloc()`, `realloc()` and `free()`")
Assisted-by: LLM
Signed-off-by: Danish Khateeb <danishkhateeb03@gmail.com>
Link: https://patch.msgid.link/20260926152414.251214-3-danishkhateeb03@gmail.com
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2026-09-30 21:27:03 +02:00
..
accounting
arch - Remove the smp_locks alternatives machinery which was used to patch out lock 2026-08-18 18:11:25 -07:00
bootconfig Bootconfig updates for v7.3: 2026-08-25 08:59:09 -07:00
bpf perf tools updates for v7.3 2026-08-22 08:47:50 -07:00
build perf build: Remove leftover feature tests for removed cxx and clang support 2026-08-12 06:17:49 -07:00
certs
cgroup
counter
crypto
debugging
dma
docs doc tools: fix 'path' typos 2026-08-11 10:43:16 -06:00
firewire
firmware
gpio
hv
iio
include tools/nolibc: check for overflow in malloc() 2026-09-30 21:27:03 +02:00
kvm/kvm_stat
laptop
leds
lib More thermal control updates for 7.3-rc1 2026-08-26 14:21:30 -07:00
memory-model
mm mm.git review status for master..mm-nonmm-stable 2026-08-23 08:07:11 -07:00
net Including fixes from Bluetooth, IPSec and Netfilter. 2026-08-27 13:53:43 -07:00
objtool Rust fixes for v7.3 2026-08-30 09:47:39 -07:00
pcmcia
perf perf tools updates for v7.3 2026-08-22 08:47:50 -07:00
platform/x86/amd
power
rcu
sched
sched_ext sched_ext: Merge branch 'for-7.3-arena-args' into for-7.3 2026-08-17 11:20:34 -10:00
scripts perf tools updates for v7.3 2026-08-22 08:47:50 -07:00
sound
spi
testing tools/nolibc: add support for pread() and pwrite() 2026-09-27 11:32:20 +02:00
thermal
time
tracing
unittests
usb
verification verification/rvgen: Use .old instead of .bak for kunit backup files 2026-08-25 13:56:53 +02:00
virtio tools/virtio: Fix control typo in trace agent comment 2026-08-19 06:38:48 -04:00
wmi
workqueue workqueue: allocate attrs for all workqueues 2026-08-10 11:47:20 -10:00
writeback
Makefile