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From: Nihal Jere <>
Subject: [musl] Dynamic linker segfault
Date: Tue, 4 Jan 2022 15:27:10 -0600	[thread overview]
Message-ID: <YdS7rrVPInqjpFTu@debussy> (raw)


ldd from master segfaults when run on [1] and [2]. It happens on
this[3] line. It seems to happen due to the intersection of a few

1. The segment at the lowest address is read-only.
2. A segment on the the same page is read/write.
3. The read/write segment has memsz > filesz.

This results in a segfault, as it tries to memset[3] on the mmap
created here[4], which has the same protection as the segment at
the lowest address (i.e. read-only).

As far as I can see, the options are to either:

a. detect this and throw an error.
b. 'or' together the protection flags of all the segments on the page.

I'm not sure what the right behavior is, but I don't think segfaulting
is right, and I'm sure there are people here what's correct.



             reply	other threads:[~2022-01-04 21:27 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-04 21:27 Nihal Jere [this message]
2022-01-04 21:42 ` Rich Felker
2022-01-05  8:56   ` Florian Weimer
2022-01-05 13:49     ` Rich Felker
2022-01-05 14:00       ` Florian Weimer
2022-01-05 15:00         ` Rich Felker
2022-01-07 13:58           ` Florian Weimer
2022-01-07 17:35             ` Rich Felker
2022-01-10 13:30               ` Florian Weimer

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