4fbb584a0
Denis Vlasenko
2006-11-24
Subject
tar: cry murder and bail out if file shrinks under us while we tar it up
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No binary (build failed)
Architecture & Compiler Flags
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Build Log
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Commit Diff GitHub →
archival/tar.c+12 -2
| @@ -59,7 +59,7 @@ struct TarHeader { /* byte offset */ | |
| typedef struct TarHeader TarHeader; | |
| /* | |
| - | ** writeTarFile(), writeFileToTarball(), and writeTarHeader() are |
| + | ** writeTarFile(), writeFileToTarball(), and writeTarHeader() are |
| ** the only functions that deal with the HardLinkInfo structure. | |
| ** Even these functions use the xxxHardLinkInfo() functions. | |
| */ | |
| @@ -397,7 +397,17 @@ static int writeFileToTarball(const char *fileName, struct stat *statbuf, | |
| off_t readSize = 0; | |
| /* write the file to the archive */ | |
| - | readSize = bb_copyfd_eof(inputFileFd, tbInfo->tarFd); |
| + | readSize = bb_copyfd_size(inputFileFd, tbInfo->tarFd, statbuf->st_size); |
| + | if (readSize != statbuf->st_size) { |
| + | /* Deadly. We record size into header first, */ |
| + | /* and then write out file. If file shrinks in between, */ |
| + | /* tar will be corrupted. So bail out. */ |
| + | /* NB: GNU tar 1.16 warns and pads with zeroes */ |
| + | /* or even seeks back and updates header */ |
| + | bb_error_msg_and_die("short read from %s", fileName); |
| + | } |
| + | /* Check that file did not grow in between? */ |
| + | /* if (safe_read(inputFileFd,1) == 1) warn but continue? */ |
| close(inputFileFd); | |
| /* Pad the file up to the tar block size */ | |
libbb/copyfd.c+1 -2
| @@ -46,8 +46,7 @@ static off_t bb_full_fd_action(int src_fd, int dst_fd, off_t size) | |
| } else if (rd < 0) { | |
| bb_perror_msg(bb_msg_read_error); | |
| break; | |
| - | } else if (rd == 0) { |
| - | /* All done. */ |
| + | } else { /* eof - all done. */ |
| status = 0; | |
| break; | |
| } | |