AskUbuntuDefault external media mount location seems to have changed in 26.04 #mount #harddrive #filesystem #2604
oshogboI 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.
Corrupting a ZFS File on Purpose
Most of the time, the whole point of ZFS is that your data does not get corrupted. But during development you sometimes need the opposite: a controlled, reproducible corruption, so you can watch self-healing kick in, see what a scrub reports, or just understand how a file maps onto the physical disk. There is no better exercise than breaking one byte on purpose and seeing ZFS notice.
sigdevelSeries 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
Wordmark#scary #ai #video #rewardhacking when #ai finds unwanted ways to score higher, whoever grants #AI such #powers like calling other tools like #ssh or full #filesystem #access is indeed acting #irresponsible #openclaw in a #terminator scenario it is most likely an evil human giving the order for #robots to kill, not #AI because #freewill of #AI is still #scifi https://dwaves.de/2026/06/04/a-conversation-with-claude-sonnet-4-6-ai-and-free-will-maybe-in-2050-but-there-is-reward-hacking/
The Eclectic Light Company [Unofficial]BSD flags are incompatible with iCloud Drive
Meteora Web🚨 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...
InnocentZeroCan 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
Security Advisory: CVE-2025-70100 - Divide By Zero in lwext4
When mounting or parsing a specially crafted EXT4 image that encodes a zero logical block size, lwext4 passes the invalid value into ext4_block_set_lb_size(), which performs arithmetic without validation and triggers a divide-by-zero crash.
Summary:
ext4_mount() reads the logical block size from the filesystem superblock and forwards it directly to ext4_block_set_lb_size() in ext4_blockdev.c. ext4_block_set_lb_size() uses lb_size in a division at line 127 without a prior zero-check, so a crafted image that encodes lb_size == 0 causes a Floating Point Exception. The process terminates immediately; under standard builds a SIGFPE is raised, under ASan the signal is intercepted and reported as FPE on address 0x55f254cc29e9.
CWE:
CWE-369 - Divide By Zero
Affected Component:
```
src/ext4_blockdev.c:127
Function: ext4_block_set_lb_size()
src/ext4.c:421
Function: ext4_mount()
```
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 or image processing. No elevated privileges are required; only local access (AV:L) to provide the malicious image is needed.
Impact:
The divide-by-zero causes an immediate process crash, 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/90
- PoC: https://github.com/sigdevel/pocs/blob/main/res/lwext4/2/sig8_2_lwext4_ext4_blockdev_c_127
- 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
Security Advisory: CVE-2025-70099 - NULL Pointer Dereference in lwext4
When parsing a specially crafted EXT4 filesystem image with malformed directory entries, lwext4 dereferences a NULL directory entry pointer in ext4_dir_en_get_name_len(), causing a segmentation fault.
Summary:
The inline helper ext4_dir_en_get_name_len() in ext4_dir.h reads the name_len field from a directory entry struct without first validating that the entry pointer is non-NULL. During directory iteration via ext4_dir_entry_next(), processing of a corrupted EXT4 image can produce a NULL (or near-NULL) entry pointer. The subsequent dereference of en->name_len at line 126 triggers a READ access at address 0x6 and crashes the process.
CWE:
CWE-476 - NULL Pointer Dereference
Affected Component:
```
include/ext4_dir.h:126
Function: ext4_dir_en_get_name_len()
src/ext4.c:3233
Function: ext4_dir_entry_next()
```
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 parsing or directory traversal. No elevated privileges are required; only local access (AV:L) to provide the malicious image is needed.
Impact:
The NULL pointer dereference causes an immediate process crash, 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/89
- PoC: https://github.com/sigdevel/pocs/blob/main/res/lwext4/1/sig11_2_1_lwext4_ext4_dir_h_126
- 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
