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author | Denys Vlasenko <vda.linux@googlemail.com> | 2016-08-19 18:23:56 +0200 |
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committer | Denys Vlasenko <vda.linux@googlemail.com> | 2016-08-19 18:43:06 +0200 |
commit | 215b0ca6e4fe466c6942d21a1bba62d97f2d5e5d (patch) | |
tree | 4fbb9563d870ce8a5f8f08015424e358a1462677 /shell/ash_doc.txt | |
parent | aedc3fe19fac368dc363050e0387d263b7e01cc6 (diff) | |
download | busybox-215b0ca6e4fe466c6942d21a1bba62d97f2d5e5d.tar.gz |
hush: fix a bug in FEATURE_SH_STANDALONE=y config. Closes 9186
Run this in a "sh SCRIPT":
sha256sum /dev/null
echo END
sha256sum is a NOEXEC applet. It runs in a forked child. Then child exit()s.
By this time, entire script is read, and buffered in a FILE object
from fopen("SCRIPT"). But fgetc() did not consume entire input.
exit() lseeks back by -9 bytes, from <eof> to 'e' in 'echo'.
(this may be libc-specific).
This change of fd position *is shared with the parent*!
Now parent can read more, and it thinks there is another "echo END".
End result: two "echo END"s are run.
Fix this by _exit()ing instead.
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'shell/ash_doc.txt')
0 files changed, 0 insertions, 0 deletions