Paul Chaignon 97303e541e bpf: Reject %p% format string in bprintf-like helpers ... [ Upstream commit f824274587 ] static const char fmt[] = "%p%"; bpf_trace_printk(fmt, sizeof(fmt)); The above BPF program isn't rejected and causes a kernel warning at runtime: Please remove unsupported %\x00 in format string WARNING: CPU: 1 PID: 7244 at lib/vsprintf.c:2680 format_decode+0x49c/0x5d0 This happens because bpf_bprintf_prepare skips over the second %, detected as punctuation, while processing %p. This patch fixes it by not skipping over punctuation. %\x00 is then processed in the next iteration and rejected. Reported-by: syzbot+e2c932aec5c8a6e1d31c@syzkaller.appspotmail.com Fixes: 48cac3f4a9 ("bpf: Implement formatted output helpers with bstr_printf") Acked-by: Yonghong Song <yonghong.song@linux.dev> Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com> Link: https://lore.kernel.org/r/a0e06cc479faec9e802ae51ba5d66420523251ee.1751395489.git.paul.chaignon@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>		2025-08-28 16:24:01 +02:00
..
preload
arraymap.c	bpf: Check percpu map value size first	2024-10-17 15:11:49 +02:00
bpf_inode_storage.c
bpf_iter.c
bpf_local_storage.c
bpf_lru_list.c	bpf: Address KCSAN report on bpf_lru_list	2024-03-01 13:21:55 +01:00
bpf_lru_list.h	bpf: Address KCSAN report on bpf_lru_list	2024-03-01 13:21:55 +01:00
bpf_lsm.c
bpf_struct_ops_types.h
bpf_struct_ops.c
bpf_task_storage.c
btf.c	bpf: Eliminate remaining "make W=1" warnings in kernel/bpf/btf.o	2024-08-19 05:44:59 +02:00
cgroup.c
core.c	bpf: Avoid __bpf_prog_ret0_warn when jit fails	2025-06-27 11:05:14 +01:00
cpumap.c	xdp: Move conversion to xdp_frame out of map functions	2024-05-17 11:50:47 +02:00
devmap.c	bpf: fix OOB devmap writes when deleting elements	2024-12-14 19:51:33 +01:00
disasm.c
disasm.h
dispatcher.c
hashtab.c	bpf: fix possible endless loop in BPF map iteration	2025-06-04 14:37:54 +02:00
helpers.c	bpf: Reject %p% format string in bprintf-like helpers	2025-08-28 16:24:01 +02:00
inode.c
Kconfig
local_storage.c
lpm_trie.c	bpf: Fix exact match conditions in trie_get_next_key()	2024-12-14 19:51:31 +01:00
Makefile
map_in_map.c	bpf: Defer the free of inner map when necessary	2024-03-26 18:21:12 -04:00
map_in_map.h	bpf: Add map and need_defer parameters to .map_fd_put_ptr()	2024-02-23 08:54:42 +01:00
map_iter.c
net_namespace.c
offload.c
percpu_freelist.c
percpu_freelist.h
prog_iter.c
queue_stack_maps.c
reuseport_array.c
ringbuf.c	bpf: Fix overrunning reservations in ringbuf	2024-07-27 10:46:06 +02:00
stackmap.c	bpf: Fix stackmap overflow check on 32-bit arches	2024-03-26 18:21:22 -04:00
syscall.c	bpf: avoid holding freeze_mutex during mmap operation	2025-05-02 07:44:21 +02:00
sysfs_btf.c
task_iter.c
tnum.c
trampoline.c	x86/ibt,ftrace: Search for __fentry__ location	2024-07-05 09:14:12 +02:00
verifier.c	bpf: fix precision backtracking instruction iteration	2025-07-17 18:30:48 +02:00