What is the purpose of the lost+found folder in Linux and Unix?

https://unix.stackexchange.com/questions/18154/what-is-the-purpose-of-the-lostfound-folder-in-linux-and-unix

#HackerNews #lostfound #Linux #Unix #filesystem #datarecovery #techsupport

Default external media mount location seems to have changed in 26.04 #mount #harddrive #filesystem #2604

https://askubuntu.com/q/1567532/612

I spent a whole blog post doing #ZFS on-disk math by hand - just to corrupt one byte and watch #OpenZFS healing process.

Interested?

Feel free to join the journey into the on-disk jungle.

https://oshogbo.com/blog/90/

#storage #FreeBSD #Linux #Storage #Filesystem

Series of publications on GPAC:
https://www.openwall.com/lists/oss-security/2026/05/30/2
https://www.openwall.com/lists/oss-security/2026/06/01/8
https://www.openwall.com/lists/oss-security/2026/06/01/9
https://www.openwall.com/lists/oss-security/2026/06/01/10
https://www.openwall.com/lists/oss-security/2026/06/01/11
https://www.openwall.com/lists/oss-security/2026/06/01/12
https://www.openwall.com/lists/oss-security/2026/06/01/13

#fuzzing #infosec #security #afl #revers #cybersecurity #bugbounty #vulnerability #opensource #linux #cve #advisory #media #filesystem

BSD flags are incompatible with iCloud Drive

https://fed.brid.gy/r/https://eclecticlight.co/2026/06/02/bsd-flags-are-incompatible-with-icloud-drive/

🚨 NEWS: Linux per sviluppatori: navigazione filesystem, permessi e comandi base — Guida operativa

Ecco i punti chiave in breve:
💡 Se sei uno sviluppatore o un sysadmin alle prime armi, il terminale Linux può sembrare un muro di testo ostile. Lo vediamo ogni giorno nei progetti che ci arrivano: sviluppatori che su WordPress sanno...

🚀 LINK: https://meteoraweb.com/analisi-dei-dati-e-metriche/linux-per-sviluppatori-navigazione-filesystem-permessi-e-comandi-base-guida-operativa

#linux #permessi #sviluppatori #comandiBase #filesystem

Can someone be kind enough to explain why "everything is a file" is such a GREAT idea that LITERALLY EVERYONE keeps hyping it up?

I'm literally losing my mind here trying to understand what makes it so great.

#linux #unix #posix #filesystem #filedescriptors #unixphilosophy

Security Advisory: CVE-2025-70101 - Out-of-Bounds Read in lwext4

When traversing the extent tree of a crafted EXT4 image, lwext4 reads past the valid extent index array in ext4_ext_binsearch_idx() due to missing validation of extent header fields, causing a segmentation fault.

Summary:
ext4_ext_binsearch_idx() in ext4_extent.c performs a binary search over extent index entries using pointers derived from the EXT_FIRST_INDEX and EXT_LAST_INDEX macros. These macros compute bounds directly from the eh_entries and eh_depth fields of the extent header without verifying their consistency. A crafted image can encode zero eh_entries alongside a non-zero eh_depth, causing the macros to return invalid pointers and the binary search at line 815 to read outside the allocated buffer. The fault is triggered during directory iteration via ext4_find_extent() and ultimately ext4_dir_entry_next().

CWE:
CWE-125 - Out-of-Bounds Read

Affected Component:

```
src/ext4_extent.c:815
Function: ext4_ext_binsearch_idx()

src/ext4_extent.c:896
Function: ext4_find_extent()
```

Affected Product:
lwext4 (Lightweight EXT4 filesystem library)

Affected Version:
lwext4 1.0.0, commit 58bcf89a121b72d4fb66334f1693d3b30e4cb9c5. Affects versions based on or equivalent to the 2016-era codebase.

Attack Conditions:
An attacker supplies a specially crafted or corrupted EXT4 image to any application that integrates lwext4 for mounting and directory traversal. No elevated privileges are required; only local access (AV:L) to provide the malicious image is needed.

Impact:
The out-of-bounds read causes an immediate process crash (SEGV on READ at address 0x521000062a28), resulting in a denial of service. No evidence of code execution was observed.

Fix / mitigation status:
The issue is addressed in lwext4 v1.0.1, released by Aladdin-R-D. Users should upgrade to v1.0.1 or apply the corresponding patch.

References

- Issue: https://github.com/gkostka/lwext4/issues/91
- PoC: https://github.com/sigdevel/pocs/blob/main/res/lwext4/3/sig11_lwext4_ext4_extent_815
- Fix: https://github.com/Aladdin-R-D/lwext4/releases/tag/v1.0.1

Credit
Alexander A. Shvedov (@sigdevel) & Daniil Dulov

#fuzzing #infosec #security #afl #revers #cybersecurity #bugbounty #vulnerability #opensource #linux #cve #advisory #EXT4 #lwext4 #filesystem