Johannes Schindelin
02b9662a6e
git_pread() saves the current file offset via lseek(fd, 0, SEEK_CUR) and later restores it. If the initial lseek fails (e.g., the fd is a pipe or otherwise non-seekable), current_offset is -1. This negative value is later passed to lseek(fd, -1, SEEK_SET) at line 16, which sets the file position to an unintended location (or fails with EINVAL on some platforms). Check the initial lseek return value and return -1 immediately if it fails, consistent with the error handling for the other lseek calls in the same function. Pointed out by Coverity. Assisted-by: Claude Opus 4.6 Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
22 lines
495 B
C
22 lines
495 B
C
#include "../git-compat-util.h"
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#include "../wrapper.h"
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ssize_t git_pread(int fd, void *buf, size_t count, off_t offset)
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{
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off_t current_offset;
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ssize_t rc;
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current_offset = lseek(fd, 0, SEEK_CUR);
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if (current_offset < 0)
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return -1;
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if (lseek(fd, offset, SEEK_SET) < 0)
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return -1;
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rc = read_in_full(fd, buf, count);
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if (current_offset != lseek(fd, current_offset, SEEK_SET))
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return -1;
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return rc;
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}
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