Date: Sat, 04 May 2019 03:41:23 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 237740] dd(1) always report false error about lseek(2) after read(2) error with 'conv=noerror' / dd(1) wrongly lseek(2)ed input file on read(2) error with 'conv=noerror' Message-ID: <bug-237740-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=237740 Bug ID: 237740 Summary: dd(1) always report false error about lseek(2) after read(2) error with 'conv=noerror' / dd(1) wrongly lseek(2)ed input file on read(2) error with 'conv=noerror' Product: Base System Version: CURRENT Hardware: Any OS: Any Status: New Severity: Affects Only Me Priority: --- Component: bin Assignee: bugs@FreeBSD.org Reporter: msl0000023508@gmail.com Created attachment 204204 --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=204204&action=edit fix-dd-noerror-lseek.diff Reporting 2 bugs in the same place. In the latest revision 341257 of 'dd.c', at https://svnweb.freebsd.org/base/head/bin/dd/dd.c?view=log , line 420, the error condition should be 'lseek(...) == -1'. The code: if (in.flags & ISSEEK && lseek(in.fd, (off_t)in.dbsz, SEEK_CUR)) should be: if (in.flags & ISSEEK && lseek(in.fd, (off_t)in.dbsz, SEEK_CUR) == -1) Another bug is, when a read(2) error occurred, read(2) may actually read something and change the file position then returning -1; when this happens the later lseek(2) call will over seeking the current position, skipping data that unrelated to the first read(2) error. The attached patch fix both bug. -- You are receiving this mail because: You are the assignee for the bug.home | help
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