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author | 2020-11-19 12:26:09 -0800 | |
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committer | 2020-11-19 12:26:10 -0800 | |
commit | e6ea60bac1ee28bb46232f8c2ecd3a3fbb9011e0 (patch) | |
tree | f119a3b701852f184b6131405470de0f3969c783 /lib | |
parent | Merge branch 'net-smc-fixes-2020-11-18' (diff) | |
parent | fail_function: Remove a redundant mutex unlock (diff) | |
download | linux-e6ea60bac1ee28bb46232f8c2ecd3a3fbb9011e0.tar.gz linux-e6ea60bac1ee28bb46232f8c2ecd3a3fbb9011e0.tar.bz2 linux-e6ea60bac1ee28bb46232f8c2ecd3a3fbb9011e0.zip |
Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Alexei Starovoitov says:
====================
1) libbpf should not attempt to load unused subprogs, from Andrii.
2) Make strncpy_from_user() mask out bytes after NUL terminator, from Daniel.
3) Relax return code check for subprograms in the BPF verifier, from Dmitrii.
4) Fix several sockmap issues, from John.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
fail_function: Remove a redundant mutex unlock
selftest/bpf: Test bpf_probe_read_user_str() strips trailing bytes after NUL
lib/strncpy_from_user.c: Mask out bytes after NUL terminator.
libbpf: Fix VERSIONED_SYM_COUNT number parsing
bpf, sockmap: Avoid failures from skb_to_sgvec when skb has frag_list
bpf, sockmap: Handle memory acct if skb_verdict prog redirects to self
bpf, sockmap: Avoid returning unneeded EAGAIN when redirecting to self
bpf, sockmap: Use truesize with sk_rmem_schedule()
bpf, sockmap: Ensure SO_RCVBUF memory is observed on ingress redirect
bpf, sockmap: Fix partial copy_page_to_iter so progress can still be made
selftests/bpf: Fix error return code in run_getsockopt_test()
bpf: Relax return code check for subprograms
tools, bpftool: Add missing close before bpftool net attach exit
MAINTAINERS/bpf: Update Andrii's entry.
selftests/bpf: Fix unused attribute usage in subprogs_unused test
bpf: Fix unsigned 'datasec_id' compared with zero in check_pseudo_btf_id
bpf: Fix passing zero to PTR_ERR() in bpf_btf_printf_prepare
libbpf: Don't attempt to load unused subprog as an entry-point BPF program
====================
Link: https://lore.kernel.org/r/20201119200721.288-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'lib')
-rw-r--r-- | lib/strncpy_from_user.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/lib/strncpy_from_user.c b/lib/strncpy_from_user.c index e6d5fcc2cdf3..122d8d0e253c 100644 --- a/lib/strncpy_from_user.c +++ b/lib/strncpy_from_user.c @@ -35,17 +35,32 @@ static inline long do_strncpy_from_user(char *dst, const char __user *src, goto byte_at_a_time; while (max >= sizeof(unsigned long)) { - unsigned long c, data; + unsigned long c, data, mask; /* Fall back to byte-at-a-time if we get a page fault */ unsafe_get_user(c, (unsigned long __user *)(src+res), byte_at_a_time); - *(unsigned long *)(dst+res) = c; + /* + * Note that we mask out the bytes following the NUL. This is + * important to do because string oblivious code may read past + * the NUL. For those routines, we don't want to give them + * potentially random bytes after the NUL in `src`. + * + * One example of such code is BPF map keys. BPF treats map keys + * as an opaque set of bytes. Without the post-NUL mask, any BPF + * maps keyed by strings returned from strncpy_from_user() may + * have multiple entries for semantically identical strings. + */ if (has_zero(c, &data, &constants)) { data = prep_zero_mask(c, data, &constants); data = create_zero_mask(data); + mask = zero_bytemask(data); + *(unsigned long *)(dst+res) = c & mask; return res + find_zero(data); } + + *(unsigned long *)(dst+res) = c; + res += sizeof(unsigned long); max -= sizeof(unsigned long); } |