From: Hou Tao <houtao1@xxxxxxxxxx> Hi, The patch set fixes several issues in bits iterator. Patch #1 fixes the kmemleak problem of bits iterator. Patch #2~#3 fix the overflow problem of nr_bits. Patch #4 fixes the potential stack corruption when bits iterator is used on 32-bit host. Patch #5 adds more test cases for bits iterator. Please see the individual patches for more details. And comments are always welcome. --- v4: * patch #1: add ack from Yafang * patch #3: revert code-churn like changes: (1) compute nr_bytes and nr_bits before the check of nr_words. (2) use nr_bits == 64 to check for single u64, preventing build warning on 32-bit hosts. * patch #4: use "BITS_PER_LONG == 32" instead of "!defined(CONFIG_64BIT)" v3: https://lore.kernel.org/bpf/20241025013233.804027-1-houtao@xxxxxxxxxxxxxxx/T/#t * split the bits-iterator related patches from "Misc fixes for bpf" patch set * patch #1: use "!nr_bits || bits >= nr_bits" to stop the iteration * patch #2: add a new helper for the overflow problem * patch #3: decrease the limitation from 512 to 511 and check whether nr_bytes is too large for bpf memory allocator explicitly * patch #5: add two more test cases for bit iterator v2: http://lore.kernel.org/bpf/d49fa2f4-f743-c763-7579-c3cab4dd88cb@xxxxxxxxxxxxxxx Hou Tao (5): bpf: Free dynamically allocated bits in bpf_iter_bits_destroy() bpf: Add bpf_mem_alloc_check_size() helper bpf: Check the validity of nr_words in bpf_iter_bits_new() bpf: Use __u64 to save the bits in bits iterator selftests/bpf: Add three test cases for bits_iter include/linux/bpf_mem_alloc.h | 3 + kernel/bpf/helpers.c | 54 +++++++++++++--- kernel/bpf/memalloc.c | 14 ++++- .../selftests/bpf/progs/verifier_bits_iter.c | 61 ++++++++++++++++++- 4 files changed, 118 insertions(+), 14 deletions(-) -- 2.29.2