Answer in brief
CVE-2024-49882 records a High severity (CVSS 7.8) vulnerability in ext4: fix double brelse() the buffer of the extents path. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | 3.7 | Not reported |
| Linux/Linuxgeneric | >=ecb94f5fdf4b72547fca022421a9dca1672bddd4 <d4574bda63906bf69660e001470bfe1a0ac524ae || >=ecb94f5fdf4b72547fca022421a9dca1672bddd4 <f9fd47c9d9548f9e47fa60098eab99dde175401d || >=ecb94f5fdf4b72547fca022421a9dca1672bddd4 <b6c29c8f3d7cb67b505f3b2f6c242d52298d1f2e || >=ecb94f5fdf4b72547fca022421a9dca1672bddd4 <32bbb59e3f18facd7201bef110010bf35819b8c3 || >=ecb94f5fdf4b72547fca022421a9dca1672bddd4 <78bbc3d15b6f443acb26e94418c445bac940d414 || >=ecb94f5fdf4b72547fca022421a9dca1672bddd4 <68a69cf60660c73990c1875f94a5551600b04775 || >=ecb94f5fdf4b72547fca022421a9dca1672bddd4 <7633407ca4ab8be2916ab214eb44ccebc6a50e1a || >=ecb94f5fdf4b72547fca022421a9dca1672bddd4 <230ee0535d01478bad9a3037292043f39b9be10b || >=ecb94f5fdf4b72547fca022421a9dca1672bddd4 <dcaa6c31134c0f515600111c38ed7750003e1b9c | d4574bda63906bf69660e001470bfe1a0ac524ae, f9fd47c9d9548f9e47fa60098eab99dde175401d, b6c29c8f3d7cb67b505f3b2f6c242d52298d1f2e, 32bbb59e3f18facd7201bef110010bf35819b8c3, 78bbc3d15b6f443acb26e94418c445bac940d414, 68a69cf60660c73990c1875f94a5551600b04775, 7633407ca4ab8be2916ab214eb44ccebc6a50e1a, 230ee0535d01478bad9a3037292043f39b9be10b, dcaa6c31134c0f515600111c38ed7750003e1b9c |
Published upstream
Oct 21, 2024
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: ext4: fix double brelse() the buffer of the extents path In ext4_ext_try_to_merge_up(), set path[1].p_bh to NULL after it has been released, otherwise it may be released twice. An example of what triggers this is as follows: split2 map split1 |--------|-------|--------| ext4_ext_map_blocks ext4_ext_handle_unwritten_extents ext4_split_convert_extents // path->p_depth == 0 ext4_split_extent // 1. do split1 ext4_split_extent_at |ext4_ext_insert_extent | ext4_ext_create_new_leaf | ext4_ext_grow_indepth | le16_add_cpu(&neh->eh_depth, 1) | ext4_find_extent | // return -ENOMEM |// get error and try zeroout |path = ext4_find_extent | path->p_depth = 1 |ext4_ext_try_to_merge | ext4_ext_try_to_merge_up | path->p_depth = 0 | brelse(path[1].p_bh) ---> not set to NULL here |// zeroout success // 2. update path ext4_find_extent // 3. do split2 ext4_split_extent_at ext4_ext_insert_extent ext4_ext_create_new_leaf ext4_ext_grow_indepth le16_add_cpu(&neh->eh_depth, 1) ext4_find_extent path[0].p_bh = NULL; path->p_depth = 1 read_extent_tree_block ---> return err // path[1].p_bh is still the old value ext4_free_ext_path ext4_ext_drop_refs // path->p_depth == 1 brelse(path[1].p_bh) ---> brelse a buffer twice Finally got the following WARRNING when removing the buffer from lru: ============================================ VFS: brelse: Trying to free free buffer WARNING: CPU: 2 PID: 72 at fs/buffer.c:1241 __brelse+0x58/0x90 CPU: 2 PID: 72 Comm: kworker/u19:1 Not tainted 6.9.0-dirty #716 RIP: 0010:__brelse+0x58/0x90 Call Trace: <TASK> __find_get_block+0x6e7/0x810 bdev_getblk+0x2b/0x480 __ext4_get_inode_loc+0x48a/0x1240 ext4_get_inode_loc+0xb2/0x150 ext4_reserve_inode_write+0xb7/0x230 __ext4_mark_inode_dirty+0x144/0x6a0 ext4_ext_insert_extent+0x9c8/0x3230 ext4_ext_map_blocks+0xf45/0x2dc0 ext4_map_blocks+0x724/0x1700 ext4_do_writepages+0x12d6/0x2a70 [...] ============================================
Quoted source text, attributed separately from HOL analysis.